A060287 Triangle formed from coefficients in expansion of Product_{i=3..infinity, j=0..i} 1/(1-x^(i-j)*y^j).

1, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 3, 3, 3, 2, 2, 2, 3, 4, 5, 5, 4, 3, 2, 3, 4, 6, 7, 8, 7, 6, 4, 3, 4, 6, 9, 12, 13, 13, 12, 9, 6, 4, 5, 8, 13, 17, 21, 21, 21, 17, 13, 8, 5, 6, 11, 18, 25, 31, 34, 34, 31, 25, 18, 11, 6, 9, 15, 26, 37, 48, 53, 58, 53, 48, 37, 26

Offset

0,22

Links

Table of n, a(n) for n=0..88.

Example

Series ends ... + 2*x^6 + 2*x^5*y + 3*x^4*y^2 + 3*x^3*y^3 + 3*x^2*y^4 + 2*x*y^5 + 2*y^6 + x^5 + x^4*y + x^3*y^2 + x^2*y^3 + x*y^4 + y^5 + x^4 + x^3*y + x^2*y^2 + x*y^3 + y^4 + x^3 + x^2*y + x*y^2 + y^3 + 1.
[1], [0, 0], [0, 0, 0], [1, 1, 1, 1], [1, 1, 1, 1, 1], [1, 1, 1, 1, 1, 1], [2, 2, 3, 3, 3, 2, 2], [2, 3, 4, 5, 5, 4, 3, 2], [3, 4, 6, 7, 8, 7, 6, 4, 3], ...

Crossrefs

Cf. A054225, A060244.

Sequence in context: A331484 A046918 A238732 * A238733 A165001 A364200

Adjacent sequences: A060284 A060285 A060286 * A060288 A060289 A060290

Keyword

easy,nonn,tabl

Author

Vladeta Jovovic, Mar 23 2001

Status

approved