OFFSET
1,2
LINKS
Eric Weisstein's World of Mathematics, Fibonacci Number
FORMULA
Conjecture: a(2k+1) = 3*2^(Prime[k-1]-1) for k>3. It appears that a(2k+1) = 3*2^k for k = {1,2,3,4,6,10,12,16,18,...} = A068499[n] Numbers n such that n! reduced modulo (n+1) is not zero. - Alexander Adamchuk, Sep 15 2006
EXAMPLE
MATHEMATICA
t=Table[s=DivisorSigma[0, n]; If[OddQ[n], s, s-1], {n, 1000000}]; lst={}; n=1; While[pos=Flatten[Position[t, n, 1, 1]]; Length[pos]>0, AppendTo[lst, pos[[1]]]; n++ ]; lst (Noe)
CROSSREFS
KEYWORD
nonn
AUTHOR
Reinhard Zumkeller, Apr 20 2005
EXTENSIONS
More terms from T. D. Noe, Jan 18 2006
STATUS
approved