OFFSET
1,7
COMMENTS
a(A045920(n)) = 0. - Reinhard Zumkeller, Mar 19 2012
LINKS
Reinhard Zumkeller, Table of n, a(n) for n = 1..10000
FORMULA
a(n) = Omega(n+1)-Omega(n), where Omega(n) (A001222) denotes the number of prime factors of n, counting multiplicity.
G.f.: ((1 - x)/x)*Sum_{p prime, k>=1} x^(p^k)/(1 - x^(p^k)). - Ilya Gutkovskiy, Mar 15 2017
MATHEMATICA
Omega[n_] := Apply[Plus, Transpose[FactorInteger[n]][[2]]]; Flatten[Append[{1}, Table[Omega[n + 1] - Omega[n], {n, 2, 100}]]]
PROG
(Haskell)
a076191 n = a076191_list !! (n-1)
a076191_list = zipWith (-) (tail a001222_list) a001222_list
-- Reinhard Zumkeller, Mar 20 2012
(PARI) a(n) = bigomega(n + 1) - bigomega(n); \\ Indranil Ghosh, Mar 15 2017
CROSSREFS
KEYWORD
easy,sign
AUTHOR
Joseph L. Pe, Nov 03 2002
EXTENSIONS
Name changed by Arkadiusz Wesolowski, Jul 27 2012
STATUS
approved