Number of (1+2)X(n+2) 0..3 arrays with every 3X3 subblock row and diagonal sum equal to 2 3 4 6 or 7 and every 3X3 column and antidiagonal sum not equal to 2 3 4 6 or 7.

A252408

Number of (1+2)X(n+2) 0..3 arrays with every 3X3 subblock row and diagonal sum equal to 2 3 4 6 or 7 and every 3X3 column and antidiagonal sum not equal to 2 3 4 6 or 7.

Terms

    a(0) =458a(1) =661a(2) =983a(3) =1551a(4) =2689a(5) =4582a(6) =7662a(7) =13777a(8) =24375a(9) =41464a(10) =75533a(11) =136287a(12) =235164a(13) =430077a(14) =781216a(15) =1360689a(16) =2491499a(17) =4538408a(18) =7962706a(19) =14582736a(20) =26596620a(21) =46939611a(22) =85931062a(23) =156803960a(24) =278103939a(25) =508821117a(26) =928615419a(27) =1653829878

External references