A053569 Sum of divisors of numbers which cannot be sum of divisors of any number.

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

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: A215972 A341249 A145604 * A310123 A293794 A115283

Adjacent sequences: A053566 A053567 A053568 * A053570 A053571 A053572

Keyword

nonn

Author

Labos Elemer, Jan 17 2000

Status

approved