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A100777 Square-factorial numbers: a(1) = 1, a(n+1) = a(n) * largest square divisor of (n+1). 0
1, 1, 1, 4, 4, 4, 4, 16, 144, 144, 144, 576, 576, 576, 576, 9216, 9216, 82944, 82944, 331776, 331776, 331776, 331776, 1327104, 33177600, 33177600, 298598400, 1194393600, 1194393600, 1194393600, 1194393600, 19110297600 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,4

COMMENTS

Complementary to A048803 which can be defined as squarefree factorials. a(1) = 1, a(n+1) = a(n)* largest squarefree divisor of (n+1). Generalization: P(signature)-factorial. a(1) = 1, a(n+1) = a(n)* Largest P(signature) divisor of (n+1), where P(signature) is an arbitrarily chosen prime signature unique for a sequence. Subsidiary sequences: Cube-factorial, pq^2 factorial,p^2q^2 factorial etc.

LINKS

Table of n, a(n) for n=1..32.

FORMULA

Partial products of A008833, largest square dividing n. - Ray Chandler, Nov 29 2004

CROSSREFS

Cf. A048803.

Sequence in context: A115639 A242954 A062732 * A309501 A024727 A024552

Adjacent sequences:  A100774 A100775 A100776 * A100778 A100779 A100780

KEYWORD

easy,nonn

AUTHOR

Amarnath Murthy, Nov 28 2004

STATUS

approved

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Last modified September 19 04:52 EDT 2019. Contains 327187 sequences. (Running on oeis4.)