0,4

A Chebyshev transform of 1/(1-x): if A(x) is the g.f. of a sequence, map it to ((1-x^2)/(1+x^2))A(x/(1+x^2)).

Transform of 1/(1+x) under the mapping g(x)->((1+x)/(1-x))g(x/(1-x)^2). - Paul Barry (pbarry(AT)wit.ie), Dec 01 2004

Multiplicative with a(p^e) = -1 if p = 2; -2 if p = 3; 1 otherwise. David W. Wilson (davidwwilson(AT)comcast.net) Jun 10, 2005.

G.f.: (1-x^2)/(1-x+x^2); a(n)=a(n-1)-a(n-2), n>2; a(n)=n*sum{k=0..floor(n/2), (-1)^k*binomial(n-k, k)/(n-k)}.

a(n)=sum{k=0..n, binomial(n+k, 2k)(2n/(n+k))(-1)^k}, n>1 - Paul Barry (pbarry(AT)wit.ie), Dec 01 2004

Moebius transform is length 6 sequence [ 1, -2, -3, 0, 0, 6].

Euler transform of length 6 sequence [ 1, -2, -1, 0, 0, 1].

a(n)=A087204(n), n>0. [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Sep 02 2008]

(PARI) {a(n)=if(n==0, 1, [2, 1, -1, -2, -1, 1][n%6+1])}

Cf. A099837, A099443, A011655, A100047, A100048, A100050.

Row sums of array A127677.

Sequence in context: A057559 A016010 A099837 this_sequence A122876 A100063 A132419

Adjacent sequences: A100048 A100049 A100050 this_sequence A100052 A100053 A100054

easy,sign,mult

Paul Barry (pbarry(AT)wit.ie), Oct 31 2004