0,2

Central terms of the triangle in A100851. - Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Mar 04 2006

Number of n-permutations of 13 objects: n, o, p, q, r, s, t, u, v, w, z, x, y with repetition allowed and containing no u's, (u-free). Permutations with repetitions! If n=0 then 1 >>12^0=1 "". (no u's.) If n=1 then 12 >>12^1=12, >> n, o, p, q, r, s, t, v, w, z, x, y. (no u's.) etc. [From Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Jun 29 2009]

N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

T. D. Noe, Table of n, a(n) for n=0..100

P. J. Cameron, Sequences realized by oligomorphic permutation groups, J. Integ. Seqs. Vol. 3 (2000), #00.1.5.

INRIA Algorithms Project, Encyclopedia of Combinatorial Structures 276

Tanya Khovanova, Recursive Sequences

S. Plouffe, Approximations de S\'{e}ries G\'{e}n\'{e}ratrices et Quelques Conjectures, Dissertation, Universit\'{e} du Qu\'{e}bec \`{a} Montr\'{e}al, 1992.

S. Plouffe, 1031 Generating Functions and Conjectures, Universit\'{e} du Qu\'{e}bec \`{a} Montr\'{e}al, 1992.

Y. Puri and T. Ward, Arithmetic and growth of periodic orbits, J. Integer Seqs., Vol. 4 (2001), #01.2.1.

G.f.: 1/(1-12x), e.g.f.: exp(12x)

a(n) = 12*a(n-1). [From Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Apr 27 2009]

A001021:=-1/(-1+12*z); [S. Plouffe in his 1992 dissertation.]

(Other) sage: [lucas_number1(n, 12, 0) for n in xrange(1, 19)]# [From Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Apr 27 2009]

a(n) = A159991(n)/A000351(n). [From Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), May 02 2009]

Sequence in context: A163448 A004191 A051051 this_sequence A159490 A000468 A076728

Adjacent sequences: A001018 A001019 A001020 this_sequence A001022 A001023 A001024

nonn,easy

N. J. A. Sloane (njas(AT)research.att.com).