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A053569 Sum of divisors of numbers which cannot be sum of divisors of any number. 0
3, 6, 13, 18, 12, 31, 18, 20, 32, 36, 24, 31, 42, 40, 30, 48, 54, 48, 38, 42, 44, 78, 72, 48, 57, 93, 72, 98, 54, 72, 90, 60, 62, 127, 84, 144, 68, 96, 144, 72, 74, 124, 140, 96, 80, 121, 126, 84, 108, 132, 120, 180, 90, 168, 144, 120, 98, 156, 217, 102, 104, 192, 162 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

See also comments in A053474.

LINKS

Table of n, a(n) for n=1..63.

FORMULA

a(n) = A000203(A007369(n)).

EXAMPLE

The 13th non-sigma number is 26. Its divisors are {26,13,2,1} of which the sum is 42. So a(13)=42. Also a(20)=42, the divisor sum of 20th term in A007369, which is 41.

CROSSREFS

Cf. A000203, A007369, A053474.

Sequence in context: A189420 A215972 A145604 * A310123 A293794 A115283

Adjacent sequences:  A053566 A053567 A053568 * A053570 A053571 A053572

KEYWORD

nonn

AUTHOR

Labos Elemer, Jan 17 2000

STATUS

approved

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Last modified March 21 01:18 EDT 2019. Contains 321356 sequences. (Running on oeis4.)