A056167 - OEIS

A056167

Numbers k such that k! is not divisible by the square of (f+1)!, where f = floor(k/2).

2, 3, 4, 5, 6, 7, 8, 9, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79

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OFFSET

1,1

COMMENTS

Values of f are in A001057 or A004526.

LINKS

Table of n, a(n) for n=1..72.

EXAMPLE

12 is here because 12!/(7!*7!) = 132/7 is not an integer. 10 is not here because 10!/(6!*6!) = 7 is an integer.

CROSSREFS

Cf. A001057, A004526.

Sequence in context: A163807 A118766 A136399 * A050759 A039274 A102487

Adjacent sequences: A056164 A056165 A056166 * A056168 A056169 A056170

KEYWORD

nonn

AUTHOR

Labos Elemer, Jul 27 2000

STATUS

approved