The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A107718 Column 1 of triangle A107717. 1
 1, 6, 57, 723, 11361, 212151, 4584081, 112480887, 3090105921, 93988998183, 3136338148017, 113945190405303, 4477940877230625, 189296643095867847, 8565988634172222609, 413169192012610306263, 21161884092470464784385 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS Equals one-half of column 0 of A107719 shift 1 place left. LINKS PROG (PARI) {a(n)=if(n<0, 0, (matrix(n+2, n+2, m, j, if(m>=j, if(m==j, 1, if(m==j+1, -3*j, polcoeff(1/sum(i=0, m-j, prod(r=0, i-1, 3*r+1)*x^i)+O(x^m), m-j)))))^-1)[n+2, 2])} CROSSREFS Cf. A107717, A107719. Sequence in context: A306030 A152170 A087659 * A308863 A000406 A305276 Adjacent sequences:  A107715 A107716 A107717 * A107719 A107720 A107721 KEYWORD nonn AUTHOR Paul D. Hanna, May 30 2005 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified April 6 16:14 EDT 2020. Contains 333276 sequences. (Running on oeis4.)