A359077 - OEIS

The OEIS is supported by the many generous donors to the OEIS Foundation.

A359077

Numbers that do not have two proper divisors with an equal sum of digits.

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

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,2

LINKS

Table of n, a(n) for n=1..68.

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: A309066 A084981 A326880 * A078453 A052425 A272074

Adjacent sequences: A359074 A359075 A359076 * A359078 A359079 A359080

KEYWORD

nonn,base

AUTHOR

Stefano Spezia, Dec 15 2022

STATUS

approved