a(1) = a(2) = a(3) = 1; for n>3, a(n) = a(n-1) + a(n-2) + a(n-3) iff n-1 is prime, otherwise a(n) = a(n-1) + 1.
A113057
a(1) = a(2) = a(3) = 1; for n>3, a(n) = a(n-1) + a(n-2) + a(n-3) iff n-1 is prime, otherwise a(n) = a(n-1) + 1.
Terms
- a(0) =1a(1) =1a(2) =1a(3) =3a(4) =4a(5) =8a(6) =9a(7) =21a(8) =22a(9) =23a(10) =24a(11) =69a(12) =70a(13) =163a(14) =164a(15) =165a(16) =166a(17) =495a(18) =496a(19) =1157a(20) =1158a(21) =1159a(22) =1160a(23) =3477a(24) =3478a(25) =3479a(26) =3480a(27) =3481a(28) =3482a(29) =10443
External references
- oeis: A113057