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A056067 Numbers n such that n! is divisible by the square of (f+d)!^2 for d=0 and d=1 (and possibly larger d), where f=floor[n/2] 1
1, 10, 11, 28, 29, 54, 55, 82, 83, 88, 89, 130, 131, 152, 153, 180, 181, 218, 219, 250, 251, 278, 279, 304, 305, 310, 311, 338, 339, 372, 373, 378, 379, 406, 407, 416, 417, 418, 419, 438, 439, 454, 455, 460, 461, 474, 475, 530, 531, 550, 551, 596, 597, 614 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Observe that all terms (except 1) are number-pairs starting with even number (e.g. 88,89).

LINKS

Table of n, a(n) for n=1..54.

EXAMPLE

For n=10 and 11, 10! or 11! are divided both by 5!^2 and 6!^2.

CROSSREFS

Cf. A056038-A056044, A056068.

Sequence in context: A300376 A136828 A136833 * A300678 A086458 A179856

Adjacent sequences:  A056064 A056065 A056066 * A056068 A056069 A056070

KEYWORD

nonn

AUTHOR

Labos Elemer, Jul 26 2000

STATUS

approved

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Last modified May 20 20:16 EDT 2019. Contains 323426 sequences. (Running on oeis4.)