A079110 Number of 2's in n# (n primorial) = 2's in A002110(n).

0, 1, 0, 0, 1, 1, 0, 0, 0, 3, 1, 1, 1, 4, 1, 1, 1, 4, 2, 2, 1, 5, 2, 4, 1, 3, 3, 11, 1, 4, 4, 2, 6, 5, 2, 5, 8, 5, 3, 7, 5, 9, 8, 7, 12, 5, 5, 8, 7, 7, 6, 16, 14, 7, 12, 11, 7, 12, 6, 10, 13, 7, 14, 12, 16, 11, 14, 10, 14, 11, 22, 12, 10, 27, 19, 18, 6, 17, 18, 16, 13, 16, 19, 16, 12, 20, 21, 12, 21, 18, 18

Offset: 0

Author

Cino Hilliard, Feb 03 2003

Keywords

• nonn
• base
• easy

Links

• Alois P. Heinz, Table of n, a(n) for n = 0..10000 (999 terms from Vincenzo Librandi)

Crossrefs

Cf. A002110, A079099.

Programs

Mathematica

DigitCount[#, 10, 2]&/@Rest[FoldList[Times, 1, Prime[Range[100]]]] (* Vincenzo Librandi, Apr 07 2014 *)

PARI

\\ See program in A079099.

Extensions

Offset corrected by Alois P. Heinz, Jul 21 2025