OFFSET
1,1
FORMULA
EXAMPLE
n = 6: d = 6^6 = 46656, a(n) = a(6) = 2935 because sigma(2935) + 46656 = 1 + 5 + 587 + 2935 + 46656 = sigma(2935 + 46656) = sigma(49591) = 1 + 101 + 491 + 49591 = 50184.
MATHEMATICA
L = {}; Do[i = 1; While[ ! ((Plus @@ Divisors[i + 6^j] == 6^j + Plus @@ Divisors[i]) && ! PrimeQ[i]), i++ ]; L = Append[L, i], {j, 1, 11}]; L (from Vit Planocka)
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Labos Elemer, Jun 01 2000
EXTENSIONS
One more term from Vit Planocka (planocka(AT)mistral.cz), Sep 23 2003
a(12)-a(23) from Donovan Johnson, Nov 30 2008
STATUS
approved