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A072163
a(n)-th factorial is the smallest factorial containing exactly n 2's, or 0 if no such number exists.
8
2, 14, 13, 30, 40, 47, 31, 46, 54, 49, 65, 76, 62, 69, 107, 78, 86, 115, 95, 121, 109, 165, 110, 113, 149, 151, 146, 137, 162, 159, 170, 191, 195, 174, 190, 196, 164, 209, 202, 173, 198, 248, 201, 262, 231, 205, 263, 233, 246, 256, 270, 244, 287, 200, 271, 250
OFFSET
1,1
EXAMPLE
a(2)=14 since 14th factorial, i.e., 14!=87178291200, contains exactly two 2's.
MATHEMATICA
Do[k = 1; While[ Count[IntegerDigits[k! ], 2] != n, k++ ]; Print[k], {n, 1, 60}]
KEYWORD
base,nonn
AUTHOR
Shyam Sunder Gupta, Jul 30 2002
EXTENSIONS
Edited and extended by Robert G. Wilson v, Jul 31 2002
STATUS
approved