Number of non-equivalent (mod D_3) ways to place 4 indistinguishable points on a triangular grid of side n so that no two of them are adjacent.

A239574

Number of non-equivalent (mod D_3) ways to place 4 indistinguishable points on a triangular grid of side n so that no two of them are adjacent.

Terms

    a(0) =0a(1) =1a(2) =24a(3) =200a(4) =1053a(5) =3932a(6) =11988a(7) =31298a(8) =73046a(9) =155880a(10) =310046a(11) =581414a(12) =1038634a(13) =1779531a(14) =2942114a(15) =4714412a(16) =7350595a(17) =11184786a(18) =16654116a(19) =24317554a(20) =34886940a(21) =49252544a(22) =68523846a(23) =94062350a(24) =127534794a(25) =170954603a(26) =226748678a(27) =297809946a(28) =387580007a(29) =500113190

External references