OFFSET
1,1
COMMENTS
The conjectured g.f. (-4*x^11 + 12*x^10 + 8*x^9 + 24*x^8 + 56*x^7 + 72*x^6 + 43*x^5 + 39*x^4 + 19*x^3 + 15*x^2 + 7*x + 3)/(4*x^12 - 5*x^6 + 1) is wrong; it matches only the first 41 terms of the sequence [R. J. Mathar, Jun 16 2009]
MATHEMATICA
vec=NestList[ #+1+Cases[ FactorInteger[ # ][ [ All, 1 ] ], _?OddQ, 1, 1 ][ [ 1 ] ]&, 3, 100 ]
NestList[1+#+Select[FactorInteger[#][[All, 1]], OddQ][[1]]&, 3, 40] (* Harvey P. Dale, Oct 08 2016 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Peter Pein, Feb 09 2009
STATUS
approved