OFFSET
1,2
MATHEMATICA
a={}; For[k=1, k<=90, k++, If[Length[Intersection[Table[Total[Part[IntegerDigits[Divisors[k]], i]], {i, DivisorSigma[0, k]-1}]]] == DivisorSigma[0, k]-1, AppendTo[a, k]]]; a
PROG
(PARI) isok(k) = my(d=setminus(Set(divisors(k)), [k])); #Set(apply(sumdigits, d)) == #d; \\ Michel Marcus, Dec 19 2022
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Stefano Spezia, Dec 15 2022
STATUS
approved