Eight bishops and one elephant on a 3 X 3 chessboard: a(n) = 2*Pell(n+1)+2*Pell(n)-2^n, with Pell = A000129.

A175658

Eight bishops and one elephant on a 3 X 3 chessboard: a(n) = 2*Pell(n+1)+2*Pell(n)-2^n, with Pell = A000129.

Terms

    a(0) =1a(1) =4a(2) =10a(3) =26a(4) =66a(5) =166a(6) =414a(7) =1026a(8) =2530a(9) =6214a(10) =15214a(11) =37154a(12) =90546a(13) =220294a(14) =535230a(15) =1298946a(16) =3149506a(17) =7630726a(18) =18476494a(19) =44714786a(20) =108168210a(21) =261575494a(22) =632367774a(23) =1528408194a(24) =3693378466a(25) =8923553734a(26) =21557263150a(27) =52071634466

External references