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A074370 Sum of the divisors of Sum_{i=1,...,n} prime(i). 1
3, 6, 18, 18, 56, 42, 90, 96, 217, 176, 378, 198, 432, 282, 630, 512, 1080, 672, 1080, 936, 1350, 912, 1440, 1404, 2268, 1760, 2480, 1832, 3420, 2400, 3960, 2472, 4032, 2840, 3990, 3240, 5400, 2856, 4608, 5200 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..40.

FORMULA

a(n) = A000203(A007504(n)). - R. J. Mathar, Apr 03 2011

EXAMPLE

sigma(prime(1) + prime(2) + prime(3)) = sigma(10) = 18, so a(3) = 18.

MAPLE

A007504 := proc(n) add( ithprime(i), i=1..n) ; end proc:

A074370 := proc(n) numtheory[sigma](A007504(n)) ; end proc: # R. J. Mathar, Apr 03 2011

MATHEMATICA

s = 0; l = {}; Do[s = s + Prime[i]; l = Append[l, DivisorSigma[1, s]], {i, 1, 100}]; l

DivisorSigma[1, #]&/@Accumulate[Prime[Range[50]]]  (* Harvey P. Dale, Mar 13 2011 *)

CROSSREFS

Sequence in context: A248324 A078318 A193433 * A174101 A088339 A064400

Adjacent sequences:  A074367 A074368 A074369 * A074371 A074372 A074373

KEYWORD

easy,nonn

AUTHOR

Joseph L. Pe, Sep 24 2002

STATUS

approved

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Last modified November 28 09:09 EST 2014. Contains 250301 sequences.