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.

A124530 Rectangular table, read by antidiagonals, such that the g.f. of row n, R_n(y), satisfies: R_n(y) = Sum_{k>=0} y^k * R_k(y)^(n*k) for n>=0, with R_0(y) = 1/(1-y).

Original entry on oeis.org

1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 3, 5, 1, 1, 1, 4, 10, 16, 1, 1, 1, 5, 16, 39, 62, 1, 1, 1, 6, 23, 71, 174, 274, 1, 1, 1, 7, 31, 113, 351, 858, 1332, 1, 1, 1, 8, 40, 166, 608, 1891, 4564, 6978, 1, 1, 1, 9, 50, 231, 961, 3535, 10888, 25793, 38873, 1, 1, 1, 10, 61, 309, 1427
Offset: 0

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Author

Paul D. Hanna, Nov 05 2006

Keywords

Comments

See table A124540, in which row n equals the n-th self-convolution of row n of A124530 (this table).

Examples

			Row g.f.s R_n(y) simultaneously satisfy:
R_n(y) = 1 + y*R_1(y)^n + y^2*R_2(y)^(2n) + y^3*R_3(y)^(3n) +...
more explicitly:
R_0 = 1 + y + y^2 + y^3 + y^4 + ...
R_1 = 1 + y*(R_1)^1 + y^2*(R_2)^2 + y^3*(R_3)^3 + y^4*(R_4)^4 + ...
R_2 = 1 + y*(R_1)^2 + y^2*(R_2)^4 + y^3*(R_3)^6 + y^4*(R_4)^8 +...
R_3 = 1 + y*(R_1)^3 + y^2*(R_2)^6 + y^3*(R_3)^9 + y^4*(R_4)^12 +...
R_4 = 1 + y*(R_1)^4 + y^2*(R_2)^8 + y^3*(R_3)^12 + y^4*(R_4)^16 +...
etc., for all rows.
Rectangular table begins:
1,1,1,1,1,1,1,1,1,1,1,1,1,...
1,1,2,5,16,62,274,1332,6978,38873,228090,1399625,8933506,...
1,1,3,10,39,174,858,4564,25793,153301,951325,6130757,40861658,...
1,1,4,16,71,351,1891,10888,66139,420235,2775981,18978873,...
1,1,5,23,113,608,3535,21844,141809,959882,6738850,48877221,...
1,1,6,31,166,961,5977,39363,271564,1949165,14487241,111115804,...
1,1,7,40,231,1427,9430,65810,480077,3637345,28502254,230271472,...
1,1,8,50,309,2024,14134,104028,798954,6363948,52370770,443997440,...
1,1,9,61,401,2771,20357,157383,1267833,10579140,91111871,...
1,1,10,73,508,3688,28396,229810,1935562,16866694,151563677,...
1,1,11,86,631,4796,38578,325860,2861457,25969694,242836861,...
1,1,12,100,771,6117,51261,450748,4116641,38819122,376841378,...
		

Crossrefs

Rows: A124531, A124532, A124533, A124534, A124535, A124536; A124537 (diagonal), A124538 (antidiagonal sums); related tables: A124539, A124540; A124460 (variant).

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)))))); R[n+1][k+1]

Formula

G.f.: A(x,y) = Sum_{n>=0} x^n*R_n(y) = Sum_{k>=0} y^k/(1 - x*R_k(y)^k).