

A069970


Numbers n such that sigma(reverse(n)) = sigma(reverse(n1)) + sigma(reverse(n2)).


0



3, 4, 352, 525, 532, 564, 572, 782, 3783, 5242, 5762, 5784, 7852, 7884, 31732, 38817, 41736, 46194, 52942, 57842, 61146, 63075, 67266, 68853, 95418
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,1


LINKS



EXAMPLE

sigma(reverse(352)) = sigma(253) = 288 = 234 + 54 = sigma(153) + sigma(53) = sigma(reverse(3521)) + sigma(reverse(3522)).


MATHEMATICA

rev[n_] := FromDigits[Reverse[IntegerDigits[n]]]; Select[Range[3, 10^5], DivisorSigma[1, rev[ # ]] == DivisorSigma[1, rev[ #  1]] + DivisorSigma[1, rev[ #  2]] &]


CROSSREFS



KEYWORD

base,nonn


AUTHOR



STATUS

approved



