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A072057 Sum of divisors of 2*prime(n)+1. 4
6, 8, 12, 24, 24, 40, 48, 56, 48, 60, 104, 124, 84, 120, 120, 108, 144, 168, 240, 168, 228, 216, 168, 180, 336, 240, 312, 264, 296, 228, 432, 264, 372, 416, 336, 408, 624, 440, 408, 348, 360, 532, 384, 572, 480, 640, 624, 600, 672, 720, 468 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

EXAMPLE

Divisors of A072055(8)=2*A000040(8)+1=2*19+1=39: {1,3,13,39}, therefore a(8)=1+3+13+39=56.

MATHEMATICA

DivisorSigma[1, #]&/@(2Prime[Range[60]]+1) (* Harvey P. Dale, Sep 17 2013 *)

PROG

(Haskell)

a072057 = a000203 . a072055  -- Reinhard Zumkeller, Oct 10 2013

CROSSREFS

a(n)=A000203(A072055(n)), A000040, A072056.

Sequence in context: A315871 A315872 A315873 * A212351 A327240 A274001

Adjacent sequences:  A072054 A072055 A072056 * A072058 A072059 A072060

KEYWORD

nonn

AUTHOR

Reinhard Zumkeller, Jun 11 2002

STATUS

approved

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Last modified June 23 18:45 EDT 2021. Contains 345402 sequences. (Running on oeis4.)