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A056061 Number of square divisors of central binomial coefficients. 6
1, 1, 1, 1, 1, 2, 1, 1, 2, 4, 1, 2, 2, 2, 2, 2, 1, 2, 1, 2, 2, 2, 1, 2, 4, 4, 8, 8, 4, 6, 2, 2, 2, 4, 2, 4, 4, 4, 2, 4, 2, 2, 2, 2, 8, 12, 4, 8, 8, 8, 8, 8, 4, 6, 2, 2, 2, 3, 2, 3, 3, 3, 4, 4, 2, 4, 2, 4, 4, 4, 1, 2, 2, 2, 4, 4, 8, 12, 2, 4, 12, 12, 4, 4, 8, 12, 12, 12, 4, 6, 8, 12, 12, 12, 8, 16, 8, 8, 6 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,6

LINKS

Table of n, a(n) for n=1..99.

FORMULA

a(n)=A046951[A001405(n)]=A000005[A000188(A001405(n)]

EXAMPLE

n=27: binomial[27,13]=20058300, its largest square-divisor is 900=30^2 so a(27)=tau[30]=8.

CROSSREFS

Cf. A001405, A046951, A000005, A000188, A056056-A056060.

Sequence in context: A131054 A166288 A056648 * A029265 A103648 A127309

Adjacent sequences:  A056058 A056059 A056060 * A056062 A056063 A056064

KEYWORD

nonn

AUTHOR

Labos Elemer Jul 26 2000

STATUS

approved

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Last modified September 30 13:31 EDT 2014. Contains 247425 sequences.