OFFSET
1,2
COMMENTS
a(496) = 991 is the last term.
Subsequence of A048242 (Numbers that are not the sum of two abundant numbers).
Giovanni Resta noticed that 991 is the largest number that is not a sum of abundant numbers.
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..496
Giovanni Resta, abundant numbers
EXAMPLE
20161 = 12 + 304 + 19845 is the sum of 3 abundant numbers and thus not in the sequence (although it is in A048242, since it is not the sum of 2 abundant numbers).
MATHEMATICA
AbundantQ[n_] := DivisorSigma[1, n] > 2 n; a = Select[Range[1000], AbundantQ[#] &]; nn = Dimensions[a][[1]]; t = Rest[CoefficientList[ Series[Product[(1 + x^a[[k]]), {k, nn}], {x, 0, a[[-1]]}], x]]; f = Flatten[Position[t, 0]]
CROSSREFS
KEYWORD
nonn,fini,full
AUTHOR
Amiram Eldar, Mar 10 2017
STATUS
approved