A052366 Number of nonnegative integer 4 X 4 matrices with sum of elements equal to n, under row and column permutations.
1, 1, 4, 10, 33, 78, 224, 549, 1403, 3292, 7677, 16934, 36581, 75732, 152949, 298784, 569636, 1056500, 1916502, 3396630, 5901524, 10051384, 16820192, 27664756, 44795247, 71442327, 112366941, 174384376, 267289440, 404838044, 606375995
Offset: 0
Keywords
Links
- Andrew Howroyd, Table of n, a(n) for n = 0..1000
Formula
G.f.: (x^34 - 4*x^33 + 6*x^32 - x^31 + 3*x^30 - 11*x^29 + 33*x^28 - 19*x^27 + 81*x^26 - 52*x^25 + 152*x^24 - 36*x^23 + 255*x^22 - 130*x^21 + 367*x^20 - 84*x^19 + 350*x^18 - 94*x^17 + 350*x^16 - 84*x^15 + 367*x^14 - 130*x^13 + 255*x^12 - 36*x^11 + 152*x^10 - 52*x^9 + 81*x^8 - 19*x^7 + 33*x^6 - 11*x^5 + 3*x^4 - x^3 + 6*x^2 - 4*x + 1)/((x^10 + x^9 - x^7 - x^6 + x^4 + x^3 - x - 1)*(x^6 - 1)^2*(x^2 + 1)^3*(x^2 - 1)^4*(x^2 + x + 1)^2*(x + 1)*(x - 1)^9).