A160649 a(1)=2. a(n) = a(n-1) + A001222(a(n-1)); where A001222(m) is the sum of prime-factorization exponents of m (or, A001222(m) is the number of primes dividing m, with multiplicity).

2, 3, 4, 6, 8, 11, 12, 15, 17, 18, 21, 23, 24, 28, 31, 32, 37, 38, 40, 44, 47, 48, 53, 54, 58, 60, 64, 70, 73, 74, 76, 79, 80, 85, 87, 89, 90, 94, 96, 102, 105, 108, 113, 114, 117, 120, 125, 128, 135, 139, 140, 144, 150, 154, 157, 158, 160, 166, 168, 173, 174, 177, 179

Offset: 1

Author

Leroy Quet, May 21 2009

Keywords

• nonn

Comments

A001222(a(n)) = A160650(n) = a(n+1) - a(n).

Links

• G. C. Greubel, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A001222, A094222, A160650.

Programs

Mathematica

NestList[# + PrimeOmega[#] &, 2, 100] (* Zak Seidov, Feb 15 2015 *)

PARI

lista(nn) = {print1(a=2, ", "); for (n=2, nn, a += bigomega(a); print1(a, ", "););} \\ Michel Marcus, May 04 2018

Extensions

Extended by Ray Chandler, Jun 16 2009