1,2

D. J. Broadhurst, On the enumeration of irreducible k-fold Euler sums and their roles in knot theory and field theory

b := proc(n) local sum; sum := 0; for d in divisors(n) do sum := sum + mobius(n/d)*(fibonacci(d+1)+fibonacci(d-1)) od; RETURN(sum/n); end; A001461 := proc(n) local i; add(b(i), i=1..n); end;

Sequence in context: A018438 A107368 A074733 this_sequence A048597 A074964 A017822

Adjacent sequences: A001458 A001459 A001460 this_sequence A001462 A001463 A001464

nonn,nice,easy

N. J. A. Sloane (njas(AT)research.att.com), David Broadhurst (D.Broadhurst(AT)open.ac.uk)