A383568
Expansion of 1/sqrt((1-x^5)^2 - 4*x^2).
Original entry on oeis.org
1, 0, 2, 0, 6, 1, 20, 6, 70, 30, 253, 140, 936, 630, 3522, 2773, 13430, 12032, 51770, 51690, 201389, 220470, 789546, 935330, 3116416, 3951949, 12373910, 16645398, 49389050, 69938416, 198048409, 293296470, 797461358, 1228136090, 3222960100, 5136602753
Offset: 0
A383550
Square array A(n,k), n >= 0, k >= 0, read by antidiagonals downwards, where A(n,k) is the number of lattice paths from (0,0) to (n,k) using steps (2,0),(0,2),(3,3).
Original entry on oeis.org
1, 0, 0, 1, 0, 1, 0, 0, 0, 0, 1, 0, 2, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 3, 1, 3, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 4, 2, 6, 2, 4, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 5, 3, 10, 6, 10, 3, 5, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 6, 4, 15, 12, 21, 12, 15, 4, 6, 0, 1
Offset: 0
Square array A(n,k) begins:
1, 0, 1, 0, 1, 0, 1, 0, 1, ...
0, 0, 0, 0, 0, 0, 0, 0, 0, ...
1, 0, 2, 0, 3, 0, 4, 0, 5, ...
0, 0, 0, 1, 0, 2, 0, 3, 0, ...
1, 0, 3, 0, 6, 0, 10, 0, 15, ...
0, 0, 0, 2, 0, 6, 0, 12, 0, ...
1, 0, 4, 0, 10, 0, 21, 0, 38, ...
0, 0, 0, 3, 0, 12, 0, 30, 0, ...
1, 0, 5, 0, 15, 0, 38, 0, 82, ...
-
a(n, k) = my(x='x+O('x^(n+1)), y='y+O('y^(k+1))); polcoef(polcoef(1/(1-x^2-y^2-x^3*y^3), n), k);
Showing 1-2 of 2 results.
Comments