Tetranacci numbers: a(n) = a(n-1) + a(n-2) + a(n-3) + a(n-4), with initial conditions a(0..3) = (0, 0, 1, 0).

A001631

Tetranacci numbers: a(n) = a(n-1) + a(n-2) + a(n-3) + a(n-4), with initial conditions a(0..3) = (0, 0, 1, 0).

Terms

    a(0) =0a(1) =0a(2) =1a(3) =0a(4) =1a(5) =2a(6) =4a(7) =7a(8) =14a(9) =27a(10) =52a(11) =100a(12) =193a(13) =372a(14) =717a(15) =1382a(16) =2664a(17) =5135a(18) =9898a(19) =19079a(20) =36776a(21) =70888a(22) =136641a(23) =263384a(24) =507689a(25) =978602a(26) =1886316a(27) =3635991a(28) =7008598a(29) =13509507

External references