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Search: id:A125073
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A125073 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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