OFFSET
1,1
EXAMPLE
Sequence consists mainly of squares of primes and of special composites like 33, 34, 35, 38, 44, 46.
MATHEMATICA
sud[x_] := Apply[Plus, IntegerDigits[x]] Do[s=sud[n]-DivisorSigma[0, n]; If[Greater[s, 0]&&IntegerQ[Sqrt[n]], Print[n]], {n, 1, 10000}]
Select[Range[80]^2, Total[IntegerDigits[#]]>DivisorSigma[0, #]&] (* Harvey P. Dale, Feb 16 2020 *)
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Labos Elemer, Sep 26 2002
EXTENSIONS
Edited by Jon E. Schoenfield, Sep 23 2018
STATUS
approved