OFFSET
1,5
LINKS
G. C. Greubel, Table of n, a(n) for n = 1..5000
FORMULA
MAPLE
seq(nops(numtheory:-factorset(2*ithprime(n)-1)), n=1..120); # Muniru A Asiru, Apr 29 2019
MATHEMATICA
PrimeNu[2*Prime[Range[100]]-1] (* Harvey P. Dale, Jan 25 2015 *)
PROG
(PARI) a(n) = omega(2*prime(n)-1); \\ Michel Marcus, Oct 01 2013
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved