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A161626 Sum of all numbers from 2*n-1 up to prime(n). 1
3, 3, 5, 7, 30, 36, 75, 85, 140, 264, 286, 450, 561, 595, 722, 966, 1242, 1296, 1612, 1815, 1881, 2257, 2496, 2924, 3577, 3876, 3978, 4293, 4399, 4730, 6298, 6693, 7373, 7519, 8829, 8991, 9775, 10591, 11102, 11970, 12870, 13068, 14766, 14980, 15587, 15805 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..46.

FORMULA

a(n) = A000217(A000040(n)) - A000217(2*n-2).

EXAMPLE

a(1) = 1+2 = 3;

a(2) = 3;

a(3) = 5;

a(5) = 9+10+11 = 30.

MAPLE

A000217 := proc(n) n*(n+1) /2 ; end:

A161626 := proc(n) A000217(ithprime(n))-A000217(2*n-2) ; end: seq(A161626(n), n=1..120) ; # R. J. Mathar, Oct 02 2009

CROSSREFS

Cf. A000027, A000040, A161570.

Sequence in context: A169942 A215777 A147095 * A217648 A105888 A335679

Adjacent sequences:  A161623 A161624 A161625 * A161627 A161628 A161629

KEYWORD

nonn,easy

AUTHOR

Juri-Stepan Gerasimov, Jun 15 2009

EXTENSIONS

Edited and corrected by R. J. Mathar, Oct 02 2009

Inserted a zero in an A-number - R. J. Mathar, Oct 23 2009

STATUS

approved

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Last modified August 8 06:27 EDT 2020. Contains 336290 sequences. (Running on oeis4.)