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A078835 Sum of the divisors of the average of consecutive odd primes. 0
7, 12, 13, 28, 24, 39, 32, 42, 72, 54, 56, 96, 78, 93, 120, 168, 127, 96, 195, 140, 121, 132, 128, 156, 216, 192, 280, 152, 360, 176, 204, 288, 403, 372, 288, 378, 288, 324, 372, 546, 384, 508, 336, 468, 252, 256, 403, 560, 384, 420, 744, 504, 384, 588, 480 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..55.

FORMULA

a(n) = A000203(A024675(n)). - Omar E. Pol, Dec 08 2019

EXAMPLE

The first pair of consecutive odd primes is 3,5, with average = 4 and sigma(4) = 7. Hence a(1) = 7. The second pair of consecutive odd primes is 5,7, with average = 6 and sigma(6) = 12, so a(2) = 12.

MATHEMATICA

Table[DivisorSigma[1, (Prime[i] + Prime[i + 1])/2], {i, 2, 101}]

DivisorSigma[1, Mean[#]]&/@Partition[Prime[Range[2, 60]], 2, 1] (* Harvey P. Dale, Dec 07 2013 *)

CROSSREFS

Cf. A000203, A024675.

Sequence in context: A205807 A075696 A061120 * A173417 A031021 A153245

Adjacent sequences:  A078832 A078833 A078834 * A078836 A078837 A078838

KEYWORD

easy,nonn

AUTHOR

Joseph L. Pe, Jan 11 2003

STATUS

approved

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Last modified December 5 11:56 EST 2021. Contains 349557 sequences. (Running on oeis4.)