2,12

Vincenzo Librandi, Table of n, a(n) for n = 2..1000

Count[IntegerDigits[#], 4]&/@FoldList[Times, 1, Prime[Range[90]]] (* Harvey P. Dale, Oct 12 2011 *)

(PARI) See program in Number of 0's in n#

Cf. A002110.

Sequence in context: A055830 A293109 A233530 * A121548 A180179 A215062

Adjacent sequences: A079120 A079121 A079122 * A079124 A079125 A079126

easy,nonn

Cino Hilliard, Feb 03 2003

approved