id:A124371 - OEIS Search Results

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a(n) = number of earlier terms a(k) such that a(k)*n is a square.

+0
2

0, 1, 1, 3, 1, 1, 1, 1, 7, 1, 1, 2, 1, 1, 1, 12, 1, 2, 1, 1, 1, 1, 1, 1, 19, 1, 3, 2, 1, 1, 1, 4, 1, 1, 1, 27, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 5, 38, 4, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 51, 1, 1, 1, 1, 1, 1, 1, 5, 1, 1, 5, 2, 1, 1, 1, 4, 64, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 6, 1, 82, 1, 1 (list; graph; listen)

	OFFSET	`1,4`
	LINKS	`Leroy Quet, Home Page (listed in lieu of email address)`
	EXAMPLE	`12a(1) = 0 and 12a(4) = 36 are the two squares made by multiplying earlier terms with 12. So a(12) = 2.`
	MATHEMATICA	`f[l_List] := Append[l, Length[Select[Sqrt /@ ((Length[l] + 1)l), IntegerQ]]]; Nest[f, {}, 105] (Chandler*)`
	CROSSREFS	`Cf. A124372.` `Sequence in context: A028264 A010122 A058663 this_sequence A147989 A119329 A054724` `Adjacent sequences: A124368 A124369 A124370 this_sequence A124372 A124373 A124374`
	KEYWORD	`easy,nonn`
	AUTHOR	`Leroy Quet Oct 27 2006`
	EXTENSIONS	`Extended by Ray Chandler (rayjchandler(AT)sbcglobal.net), Oct 29 2006`

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Last modified November 23 17:09 EST 2009. Contains 167438 sequences.

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