A250743 Numerator of the harmonic mean of the first n positive Fibonacci numbers.

1, 1, 6, 24, 150, 720, 1560, 87360, 1670760, 20420400, 1999157160, 13085392320, 3302971111440, 103154328557280, 1348374437570160, 67598505136850688, 114701988497522458032, 2307534121538392979232, 10183789060049355548733936

Offset

1,3

Links

Colin Barker, Table of n, a(n) for n = 1..120

Example

a(4) = 24 because the first 4 positive Fibonacci numbers are [1,1,2,3], and 4/(1/1+1/1+1/2+1/3) = 24/17.

Prog

(PARI) s=vector(30); f=Vec(x/(1-x-x^2)+O(x^(#s+1))); n=d=0; for(k=1, #s, n++; d+=1/f[k]; s[k]=numerator(n/d)); s

Crossrefs

Cf. A000045 (Fibonacci numbers), A250744 (denominators).

Sequence in context: A126267 A026947 A366757 * A265883 A330498 A165491

Adjacent sequences: A250740 A250741 A250742 * A250744 A250745 A250746

Keyword

nonn,frac

Author

Colin Barker, Nov 27 2014

Status

approved