0,2

With interpolated zeros this has a(n)=(6*0^n + 4^n + (-4)^n + 4*2^n + 4*(-2)^n)/16 and counts closed walks of length n at a vertex of the 4-cube [Typo corrected by Alexander R. Povolotsky (pevnev(AT)juno.com), May 26 2008]

Ghislain R. Franssens, On a Number Pyramid Related to the Binomial, Deleham, Eulerian, MacMahon and Stirling number triangles, Journal of Integer Sequences, Vol. 9 (2006), Article 06.4.1.

G. R. Franssens, On a number pyramid related to the binomial, Deleham, Eulerian, MacMahon and Stirling number triangles, Journal of Integer Sequences, Vol. 9 (2006), Article 06.4.1.

G.f.: (1-16x+24x^2)/((1-4x)(1-16x)); a(n)=3*0^n/8+16^n/8+4^n/2.

E.g.f.: cosh^4(x). O.g.f.: 1/(1-4*1*x/(1-3*2*x/(1-2*3*x/(1-1*4*x)))) (continued fraction). - Peter Bala (pbala(AT)toucansurf.com), Nov 13 2006

(-1)^n*a(n)=Sum_{k, 0<=k<=n} A086872(n,k)*(-5)^(n-k). - Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Aug 17 2007

Essentially the same as A075878. - Kang Seonghoon (lifthrasiir(AT)gmail.com), Oct 09 2008

Cf. A026244, A081294, A054879, A121822.

Cf. A075878. [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Sep 08 2008]

Sequence in context: A034385 A074637 A075878 this_sequence A128573 A052675 A141010

Adjacent sequences: A092809 A092810 A092811 this_sequence A092813 A092814 A092815

easy,nonn

Paul Barry (pbarry(AT)wit.ie), Mar 11 2004