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A113356 Column 0 of triangle A113355, which is the matrix square of A113350. 4
1, 4, 18, 112, 965, 10957, 156699, 2727793, 56306695, 1350043964, 36979531548, 1141573025171, 39272377323692, 1491452150268435, 62027842189908230, 2805631215820328991, 137199563717151509076, 7215932308408758314446 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Table of n, a(n) for n=0..17.

FORMULA

a(n) = A113346(n+1) - 1, where A113346 equals column 0 of triangle A113345 (=A113340^2).

PROG

(PARI) a(n)=local(A, B); A=matrix(1, 1); A[1, 1]=1; for(m=2, n+1, B=matrix(m, m); for(i=1, m, for(j=1, i, if(i<3 || j==i || j>m-1, B[i, j]=1, if(j==1, B[i, 1]=1, B[i, j]=(A^(2*j-1))[i-j+1, 1])); )); A=B); (matrix(#A, #A, r, c, if(r>=c, (A^(2*c))[r-c+1, 1]))^2)[n+1, 1]

CROSSREFS

Cf. A113340, A113350, A113355, A113357 (column 1), A113358 (column 2), A113359 (column 3).

Sequence in context: A000986 A143920 A233534 * A062805 A326093 A222584

Adjacent sequences: A113353 A113354 A113355 * A113357 A113358 A113359

KEYWORD

nonn

AUTHOR

Paul D. Hanna, Nov 08 2005

STATUS

approved

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Last modified January 30 15:41 EST 2023. Contains 359945 sequences. (Running on oeis4.)