Number of 4-member subsets of [4*n] whose elements sum to a multiple of n.

Terms

a(0) =0a(1) =1a(2) =38a(3) =165a(4) =460a(5) =969a(6) =1782a(7) =2925a(8) =4508a(9) =6545a(10) =9158a(11) =12341a(12) =16236a(13) =20825a(14) =26262a(15) =32509a(16) =39740a(17) =47905a(18) =57190a(19) =67525a(20) =79116a(21) =91881a(22) =106038a(23) =121485a(24) =138460a(25) =156849a(26) =176902a(27) =198485a(28) =221868a(29) =246905