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A074793 Sum of prime powers less than or equal to n. 2
0, 2, 5, 9, 14, 14, 21, 29, 38, 38, 49, 49, 62, 62, 62, 78, 95, 95, 114, 114, 114, 114, 137, 137, 162, 162, 189, 189, 218, 218, 249, 281, 281, 281, 281, 281, 318, 318, 318, 318, 359, 359, 402, 402, 402, 402, 449, 449, 498, 498, 498, 498, 551, 551, 551, 551, 551 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Harvey P. Dale, Table of n, a(n) for n = 1..1000

FORMULA

Is a(n) asymptotic to c*n^2/log(n) with c=0.55...?

EXAMPLE

a(10)=38 because 2,3,4,5,7,8,9 are the prime powers less than or equal to 10 and 2+3+4+5+7+8+9 = 38

MATHEMATICA

Accumulate[Table[If[PrimePowerQ[n], n, 0], {n, 60}]] (* Harvey P. Dale, Oct 04 2019 *)

PROG

(PARI) a(n)=sum(k=1, n, k*if(omega(k)-1, 0, 1))

CROSSREFS

Cf. A034387.

Sequence in context: A126326 A284916 A070986 * A161767 A235333 A060139

Adjacent sequences:  A074790 A074791 A074792 * A074794 A074795 A074796

KEYWORD

nonn

AUTHOR

Benoit Cloitre, Sep 07 2002

STATUS

approved

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Last modified May 28 13:20 EDT 2020. Contains 334683 sequences. (Running on oeis4.)