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Search: id:A028310
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| A028310 |
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Expansion of (1-x+x^2)/(1-x)^2. |
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+0
12
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| 1, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71
(list; graph; listen)
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OFFSET
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0,3
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COMMENT
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Molien series for ring of Hamming weight enumerators of self-dual codes (with respect to Euclidean inner product) of length n over GF(4).
Engel expansion of e (see A006784 for definition) [when offset by 1] - Henry Bottomley (se16(AT)btinternet.com), Dec 18 2000
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LINKS
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G. Nebe, E. M. Rains and N. J. A. Sloane, Self-Dual Codes and Invariant Theory, Springer, Berlin, 2006.
E. M. Rains and N. J. A. Sloane, Self-dual codes, pp. 177-294 of Handbook of Coding Theory, Elsevier, 1998 (Abstract, pdf, ps).
Index entries for Molien series
Index entries for sequences related to Engel expansions
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FORMULA
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Binomial transform is A005183. - Paul Barry (pbarry(AT)wit.ie), Jul 21 2003
G.f.: (1-x+x^2)/(1-x)^2 = (1-x^6)/((1-x)(1-x^2)(1-x^3)) = (1+x^3)/((1-x)*(1-x^2)).
Euler transform of length 6 sequence [ 1, 1, 1, 0, 0, -1]. - Michael Somos Jul 30 2006
a(n) = Sum_{k, 0<=k<=n} A123110(n,k). [From Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Oct 06 2009]
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PROGRAM
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(PARI) a(n)=(n==0)+max(n, 0)
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CROSSREFS
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Apart from the extra initial 1, same as A000027.
Sequence in context: A069782 A088480 A061019 this_sequence A097045 A118759 A118760
Adjacent sequences: A028307 A028308 A028309 this_sequence A028311 A028312 A028313
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KEYWORD
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nonn,easy,mult
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AUTHOR
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N. J. A. Sloane (njas(AT)research.att.com).
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