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.

A232973 Dziemianczuk's array S(i,j) read by antidiagonals.

Original entry on oeis.org

1, 3, 6, 15, 33, 60, 81, 189, 378, 675, 459, 1107, 2349, 4509, 7992, 2673, 6588, 14553, 29403, 55188, 97416, 15849, 39663, 90207, 189351, 371358, 687258, 1209951, 95175, 240894, 560115, 1211031, 2458998, 4727565, 8664813, 15227190, 576963, 1473147, 3485187
Offset: 0

Views

Author

N. J. A. Sloane, Dec 05 2013

Keywords

Examples

			Array begins:
     1,     3,     15,      81,      459,      2673,     15849, ...
     6,    33,    189,    1107,     6588,     39663,    240894, ...
    60,   378,   2349,   14553,    90207,    560115,   3485187, ...
   675,  4509,  29403,  189351,  1211031,   7715331,  49045662, ...
  7992, 55188, 371358, 2458998, 16112925, 104838219, 678790125, ...
  ...
		

Crossrefs

See A122868 and A232969 for leading row row and column.

Programs

  • PARI
    \\ Dziemianczuk, Proposition 1
    S(n,k)=sum(i=0,n+k,sum(j=0,i,binomial(k,j)*binomial(j,i-j)*binomial(2*k+n-i,k)));
    A=[]; for(i=1,10,A=concat(A,vector(i,j,S(j-1,i-1))));
    A \\ Lars Blomberg, Jul 20 2017

Extensions

a(15)-a(38) from Lars Blomberg, Jul 20 2017