

A131787


a(n) = a(n1) + (number of terms, from among the first (n1) terms of the sequence, which are coprime to the nth Fibonacci number).


1



1, 2, 3, 5, 8, 11, 17, 23, 28, 35, 45, 51, 63, 76, 83, 92, 108, 117, 135, 144, 156, 177, 199, 205, 224, 249, 264, 279, 307, 319, 349, 364, 385, 418, 443, 456, 492, 529, 553, 566, 606, 629, 671, 696, 713, 758, 804, 817, 862, 899, 929, 962, 1014, 1041, 1089, 1114
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OFFSET

1,2


LINKS

Table of n, a(n) for n=1..56.


EXAMPLE

The 6th Fibonacci number is 8. Of the first 5 terms, only terms a(1)=1, a(3)=3 and a(4) = 5 are coprime to 8. Since there are 3 such terms, a(6) = a(5) + 3 = 11.


MAPLE

with(combinat): a[1]:= 1: for n from 2 to 55 do ct := 0: for j to n1 do if gcd(a[j], fibonacci(n)) = 1 then ct := ct+1 else ct := ct end if end do: a[n]:= a[n1]+ct end do: seq(a[n], n = 1 .. 55); # Emeric Deutsch, Jul 24 2007


CROSSREFS

Cf. A131788.
Sequence in context: A039847 A046938 A060677 * A091498 A227562 A000511
Adjacent sequences: A131784 A131785 A131786 * A131788 A131789 A131790


KEYWORD

nonn


AUTHOR

Leroy Quet, Jul 15 2007


EXTENSIONS

More terms from Joshua Zucker and Emeric Deutsch, Jul 18 2007


STATUS

approved



