A120256 a(n) = number of terms in the n-th row of A120255(n) = number of terms in A001177 equal to n.

1, 0, 1, 1, 1, 2, 1, 2, 2, 2, 1, 10, 1, 2, 5, 4, 1, 10, 3, 11, 5, 2, 1, 55, 4, 2, 12, 11, 1, 52, 3, 8, 5, 2, 5, 133, 7, 4, 5, 46, 3, 52, 1, 27, 22, 6, 1, 260, 6, 40, 5, 11, 3, 100, 13, 78, 27, 6, 3, 874, 3, 4, 22, 48, 5, 52, 7, 27, 29, 116, 3, 1319, 3, 8, 36, 23, 13, 116, 3, 444, 112, 4, 1, 1834

Offset

1,6

Links

T. D. Noe, Table of n, a(n) for n=1..300

Example

Fibonacci(9) = 34; and the divisors of 34 are 1, 2, 17 and 34. Of these divisors, 1 and 2 divide earlier Fibonacci numbers, 17 and 34 do not. So a(9) = 2.

Mathematica

f[t_] := Append[t, Select[Divisors[Fibonacci[Length[t] + 1]], FreeQ[Flatten[t], # ] &]]; Length /@ Nest[f, {}, 85] (* Ray Chandler, Jun 14 2006 *)

Crossrefs

Cf. A120255, A001177.

Sequence in context: A327640 A300648 A318450 * A300647 A114811 A275675

Adjacent sequences: A120253 A120254 A120255 * A120257 A120258 A120259

Keyword

nonn

Author

Leroy Quet, Jun 13 2006

Extensions

Extended by Ray Chandler, Jun 14 2006

Status

approved