A351742 Number of partitions of 2n into n parts of size 1, 5, 10 or 25.
1, 0, 0, 0, 1, 0, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 1, 0, 1, 1, 1, 0, 2, 1, 1, 1, 2, 1, 1, 1, 2, 2, 1, 1, 3, 2, 1, 1, 3, 2, 2, 1, 3, 3, 2, 1, 4, 3, 2, 2, 4, 3, 3, 2, 4, 4, 3, 2, 5, 4, 3, 3, 5, 4, 4, 3, 5, 5, 4, 3, 7, 5, 4, 4, 7, 5, 5, 4, 7, 7, 5, 4, 8, 7, 5
Offset: 0
Examples
a(0) = 1: []. a(4) = 1: [{5}^1,{1}^3]. a(24) = 2: [{5}^6,{1}^18], [{25}^1,{1}^23]. a(36) = 3: [{5}^9,{1}^27], [{10}^4,{1}^32], [{25}^1,{5}^3,{1}^32].
Links
- Alois P. Heinz, Table of n, a(n) for n = 0..10000
- Index entries for linear recurrences with constant coefficients, signature (0,0,0,1,0,0,0,0,1,0,0,0,-1,0,0,0,0,0,0,0,0,0,0,1,0,0,0,-1,0,0,0,0,-1,0,0,0,1).
Crossrefs
Cf. A351725.
Formula
G.f.: -1/(x^37-x^33-x^28+x^24-x^13+x^9+x^4-1).
a(n) = A351725(2n,n).