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A359077
Numbers that do not have two proper divisors with an equal sum of digits.
2
1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 23, 25, 26, 27, 28, 29, 31, 32, 33, 34, 35, 37, 38, 39, 41, 43, 45, 46, 47, 49, 51, 53, 55, 56, 57, 58, 59, 61, 62, 64, 65, 67, 68, 69, 71, 73, 74, 75, 76, 77, 78, 79, 82, 83, 85, 86, 87, 89
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
Complement of A359076.
Cf. A000005, A007953, A359075 (all the divisors).
Sequence in context: A377540 A084981 A326880 * A078453 A052425 A272074
KEYWORD
nonn,base
AUTHOR
Stefano Spezia, Dec 15 2022
STATUS
approved