A232973 Dziemianczuk's array S(i,j) read by antidiagonals.
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
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, ... ...
Links
- Lars Blomberg, Table of n, a(n) for n = 0..5049 (The first 100 antidiagonals)
- M. Dziemianczuk, Counting Lattice Paths With Four Types of Steps, Graphs and Combinatorics, September 2013, DOI 10.1007/s00373-013-1357-1.
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