id:A125073 - OEIS Search Results

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a(n) = sum of the exponents in the prime-factorization of n which are triangular numbers.

+0
2

0, 1, 1, 0, 1, 2, 1, 3, 0, 2, 1, 1, 1, 2, 2, 0, 1, 1, 1, 1, 2, 2, 1, 4, 0, 2, 3, 1, 1, 3, 1, 0, 2, 2, 2, 0, 1, 2, 2, 4, 1, 3, 1, 1, 1, 2, 1, 1, 0, 1, 2, 1, 1, 4, 2, 4, 2, 2, 1, 2, 1, 2, 1, 6, 2, 3, 1, 1, 2, 3, 1, 3, 1, 2, 1, 1, 2, 3, 1, 1, 0, 2, 1, 2, 2, 2, 2, 4, 1, 2, 2, 1, 2, 2, 2, 1, 1, 1, 1, 0, 1, 3, 1, 4, 3 (list; graph; listen)

	OFFSET	`1,6`
	LINKS	`Leroy Quet, Home Page (listed in lieu of email address)`
	EXAMPLE	`The prime-factorzation of 360 is 2^3 3^2 5^1. There are two exponents in this factorization which are triangular numbers, 1 and 3. So a(360) = 1 + 3 = 4.`
	MATHEMATICA	`f[n_] := Plus @@ Select[Last /@ FactorInteger[n], IntegerQ[Sqrt[8# + 1]] &]; Table[f[n], {n, 110}] (Chandler)`
	CROSSREFS	`Cf. A125072.` `Sequence in context: A035215 A147654 A071467 this_sequence A071461 A091829 A104512` `Adjacent sequences: A125070 A125071 A125072 this_sequence A125074 A125075 A125076`
	KEYWORD	`nonn`
	AUTHOR	`Leroy Quet Nov 18 2006`
	EXTENSIONS	`Extended by Ray Chandler (rayjchandler(AT)sbcglobal.net), Nov 19 2006`

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Last modified December 17 23:40 EST 2009. Contains 171025 sequences.

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