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A053569
Sum of divisors of numbers which cannot be sum of divisors of any number.
1
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
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
KEYWORD
nonn
AUTHOR
Labos Elemer, Jan 17 2000
STATUS
approved