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A109319 Row sums of triangle T=A109316 where T(n,k) = [T^2](n-1,k) + [T^2](n-2,k-1) and T^2 is the matrix square of A109316. 3
1, 2, 5, 15, 55, 235, 1119, 5775, 31663, 182087, 1087927, 6706823, 42433735, 274403575, 1807700679, 12099813111, 82113733447, 563992581079, 3914861387495, 27429176467703, 193781828188615, 1379223584026967 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Table of n, a(n) for n=0..21.

PROG

(PARI) {a(n)=local(A=Mat(1), B); for(m=1, n+1, B=matrix(m, m); for(i=1, m, for(j=1, i, if(j==i, B[i, j]=1, if(i==2, B[i, j]=1, B[i, j]=(A^2)[i-1, j]+if(j>1, (A^2)[i-2, j-1]))); )); A=B); return(sum(k=0, n, A[n+1, k+1]))}

CROSSREFS

Cf. A109316 (triangle), A109317 (column 0), A109318 (column 2).

Sequence in context: A051295 A009383 A104429 * A059219 A242275 A137533

Adjacent sequences:  A109316 A109317 A109318 * A109320 A109321 A109322

KEYWORD

nonn

AUTHOR

Paul D. Hanna, Jul 07 2005

STATUS

approved

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Last modified November 22 00:32 EST 2019. Contains 329383 sequences. (Running on oeis4.)