Let v(0) be the column vector (1,0,0,0)'; for n>0, let v(n) = [1 1 1 1 / 1 1 1 0 / 1 1 0 0/ 1 0 0 0] v(n-1). Sequence gives third entry of v(n).

A091024

Let v(0) be the column vector (1,0,0,0)'; for n>0, let v(n) = [1 1 1 1 / 1 1 1 0 / 1 1 0 0/ 1 0 0 0] v(n-1). Sequence gives third entry of v(n).

Terms

    a(0) =0a(1) =1a(2) =2a(3) =7a(4) =19a(5) =56a(6) =160a(7) =462a(8) =1329a(9) =3828a(10) =11021a(11) =31735a(12) =91376a(13) =263108a(14) =757588a(15) =2181389a(16) =6281058a(17) =18085587a(18) =52075371a(19) =149945056a(20) =431749580a(21) =1243173370a(22) =3579575053a(23) =10306975580a(24) =29677753369a(25) =85453685055a(26) =246054079584

External references