cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A124539 Triangle, read by rows, where row n equals the inverse binomial transform of column n in the rectangular table A124530.

Original entry on oeis.org

1, 1, 0, 1, 1, 0, 1, 4, 1, 0, 1, 15, 8, 1, 0, 1, 61, 51, 14, 1, 0, 1, 273, 311, 138, 24, 1, 0, 1, 1331, 1901, 1191, 349, 42, 1, 0, 1, 6977, 11838, 9693, 4100, 868, 76, 1, 0, 1, 38872, 75556, 76950, 43257, 13459, 2163, 142, 1, 0, 1, 228089, 495146, 606275, 430517
Offset: 0

Views

Author

Paul D. Hanna, Nov 05 2006

Keywords

Comments

In table A124530, the g.f. of row n, R_n(y), simultaneously satisfies: R_n(y) = Sum_{k>=0} y^k*R_k(y)^(n*k) for n>=0.

Examples

			Triangle begins:
1;
1, 0;
1, 1, 0;
1, 4, 1, 0;
1, 15, 8, 1, 0;
1, 61, 51, 14, 1, 0;
1, 273, 311, 138, 24, 1, 0;
1, 1331, 1901, 1191, 349, 42, 1, 0;
1, 6977, 11838, 9693, 4100, 868, 76, 1, 0;
1, 38872, 75556, 76950, 43257, 13459, 2163, 142, 1, 0;
1, 228089, 495146, 606275, 430517, 180000, 43274, 5442, 272, 1, 0; ...
		

Crossrefs

Cf. A124530 (table).

Programs

  • PARI
    T(n,k)=local(m=max(n,k),R);R=vector(m+1,r,vector(m+1,c,if(r==1 || c<=2,1,r^(c-2)))); for(i=0,m, for(r=0,m, R[r+1]=Vec(sum(c=0,m, x^c*Ser(R[c+1])^(r*c)+O(x^(m+1)))))); Vec(subst(Ser(vector(n+1, j, R[j][n+1])), x, x/(1+x))/(1+x))[k+1]

Formula

Secondary diagonal T(n+1,n) = 2^n + 2n.