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A104886 Sequence A048138, the number of times that a positive integer occurs as the sum of proper divisors, if Goldbach partitions (two odd primes, which account for most of the values) are ignored. 0
0, 1, 1, 0, 2, 1, 2, 0, 1, 0, 1, 1, 2, 1, 2, 0, 1, 0, 2, 1, 2, 0, 1, 0, 1, 0, 1, 0, 1, 2, 2, 1, 1, 0, 1, 0, 1, 0, 3, 1, 2, 1, 2, 0, 2, 0, 1, 1, 2, 0, 0, 0, 2, 1, 1, 2, 1, 0, 1, 0, 2, 1, 3, 1, 1, 0, 1, 0, 1, 0, 1, 2, 3, 0, 3, 0, 1, 0, 1, 2, 1, 0, 1, 0, 1, 1, 0, 1, 2, 0, 2, 0, 1, 0, 0, 2 (list; graph; refs; listen; history; text; internal format)
OFFSET

2,5

LINKS

Table of n, a(n) for n=2..97.

FORMULA

a(n) = number of m such that the sum of the proper divisors of m is n, ignoring m if m is the product of two different odd primes.

EXAMPLE

a(13)=1 because s(27)=1+3+9 and s(35)=1+5+7=13 however 35's factors 3 and 5 are a Goldbach partition, so 35 is not counted.

CROSSREFS

Cf. A048138, A001065, A061358.

Sequence in context: A283760 A070088 A131851 * A215604 A139351 A285677

Adjacent sequences:  A104883 A104884 A104885 * A104887 A104888 A104889

KEYWORD

nonn

AUTHOR

Nathan McNew (agreatnate(AT)yahoo.com), Mar 29 2005

STATUS

approved

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Last modified May 26 17:36 EDT 2019. Contains 323597 sequences. (Running on oeis4.)