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 A113986 Column 3 of triangle A113983; also a(n) = A113983(n+2,2) + [A113983^2](n+1,2). 4
 1, 4, 13, 43, 153, 603, 2657, 13111, 72273, 443147, 3007077, 22462571, 183744033, 1637653579, 15828157233, 165167123583, 1853228997585, 22274643111107, 285799117829549, 3902028545084315, 56522214876304249, 866295289106559595 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 LINKS FORMULA a(n) = [A113983^3](n, 0) + [A113983^4](n-1, 0) = A113994(n) + A113995(n-1). PROG (PARI) a(n)=local(A, B); A=Mat(1); for(m=2, n+4, B=matrix(m, m); for(i=1, m, for(j=1, i, if(i<3 || j==1 || j==i, B[i, j]=1, B[i, j]=A[i-1, j-1]+(A^2)[i-2, j-1]); )); A=B); A[n+4, 4] CROSSREFS Cf. A113983, A113984 (column 1), A113985 (column 2), A113987 (column 4). Sequence in context: A003688 A033434 A297928 * A149426 A042767 A286175 Adjacent sequences:  A113983 A113984 A113985 * A113987 A113988 A113989 KEYWORD nonn AUTHOR Paul D. Hanna, Nov 12 2005 STATUS approved

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Last modified December 1 08:44 EST 2021. Contains 349426 sequences. (Running on oeis4.)