A103287 - OEIS

A103287

Main diagonal of triangle A103286, in which row n+1 is formed by sorting, in ascending order, the result of the convolution of row n with {2,1}.

1, 2, 5, 12, 30, 77, 202, 540, 1464, 4014, 11101, 30910, 86542, 243416, 687364, 1947736, 5536216, 15779646, 45088304, 129124925, 370550378, 1065368994, 3068348448, 8851297414, 25571726480, 73981434516, 214317561452

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OFFSET

0,2

LINKS

Table of n, a(n) for n=0..26.

FORMULA

a(n) ~ 3^n*log_3(n)/(18n) (conjecture).

PROG

(PARI) {a(n)=local(A=vector(n+1, i, vector(i)), B); A[1][1]=1; for(k=1, n, B=vector(k+1); B[1]=2*A[k][1]; B[k+1]=A[k][k]; for(i=2, k, B[i]=2*A[k][i]+A[k][i-1]); A[k+1]=vecsort(B)); return(A[n+1][n+1])}

CROSSREFS

Cf. A103286, A103285.

Sequence in context: A024851 A188378 A145267 * A136704 A120895 A101785

Adjacent sequences: A103284 A103285 A103286 * A103288 A103289 A103290

KEYWORD

nonn

AUTHOR

Paul D. Hanna, Jan 28 2005

STATUS

approved