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
Offset: 0
Keywords
Programs
-
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])}
Formula
a(n) ~ 3^n*log_3(n)/(18n) (conjecture).