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A166886
Column 2 of triangle
A166884
.
3
1, 2, 9, 62, 593, 7266, 108720, 1922166, 39212154, 906623004, 23429034168, 669203550906, 20935080981744, 711872134399868, 26142553369667634, 1031146768716808794, 43475757877044427198, 1951261759908828697902
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OFFSET
1,2
COMMENTS
Triangle
A166884
transforms diagonals in the triangle
A166880
of coefficients in the successive iterations of x+x^2+x^3.
LINKS
Table of n, a(n) for n=1..18.
PROG
(PARI) {a(n)=local(F=x, M, N, P, m=n+1); M=matrix(m+2, m+2, r, c, F=x; for(i=1, r+c-2, F=subst(F, x, x+x^2+x^3+x*O(x^(m+2)))); polcoeff(F, c)); N=matrix(m+1, m+1, r, c, M[r, c]); P=matrix(m+1, m+1, r, c, M[r+1, c]); (P~*N~^-1)[n+2, 2]}
CROSSREFS
Cf.
A166880
,
A166884
,
A166885
,
A166887
.
Sequence in context:
A052820
A213528
A100262
*
A212413
A003577
A085928
Adjacent sequences:
A166883
A166884
A166885
*
A166887
A166888
A166889
KEYWORD
nonn
AUTHOR
Paul D. Hanna
, Nov 21 2009
STATUS
approved
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Last modified September 7 09:52 EDT 2024. Contains 375730 sequences. (Running on oeis4.)