A079135 Number of 7's in n# (n primorial) = 7's in A002110(n).

0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 2, 1, 2, 1, 3, 2, 3, 3, 2, 2, 5, 4, 5, 5, 3, 2, 6, 9, 4, 3, 10, 7, 2, 4, 2, 13, 2, 5, 4, 6, 9, 6, 6, 9, 7, 10, 9, 11, 10, 8, 5, 5, 7, 6, 10, 16, 10, 14, 12, 14, 10, 16, 13, 10, 12, 14, 13, 16, 17, 13, 20, 14, 11, 12, 8, 10, 15, 17, 9, 16, 15, 26, 21, 18, 19, 20, 28, 20, 12

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, 7]&/@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