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 A102921 Column 0 of triangle A102920, which equals the matrix square of A102098. 3
 1, 3, 36, 1036, 56355, 5045370, 679409158, 129195427716, 33114233390505, 11038606786054201, 4652371578279864792, 2423023045813285312020, 1530233703568825263174101, 1153422053136775523883308988 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS Equals the bisection of A102917. Triangle A102098 shifts each column up 1 row under matrix cube. LINKS PROG (PARI) {a(n)=if(n==0, 2, polcoeff(2-sum(k=0, n-1, a(k)*x^k*prod(j=2, k\2+2, 1-j*x +x*O(x^n))), n))} /* at even-indices n=0, 2, 4, .. */ CROSSREFS Cf. A102920, A102098, A102917. Sequence in context: A132912 A303866 A126447 * A265475 A233197 A300770 Adjacent sequences:  A102918 A102919 A102920 * A102922 A102923 A102924 KEYWORD nonn AUTHOR Paul D. Hanna, Jan 21 2005 STATUS approved

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Last modified March 20 20:14 EDT 2019. Contains 321352 sequences. (Running on oeis4.)