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 A359074 Numbers that have at least two divisors with an equal sum of digits. 4
 10, 12, 18, 20, 21, 22, 24, 27, 30, 36, 40, 42, 44, 45, 48, 50, 52, 54, 60, 63, 66, 70, 72, 80, 81, 84, 88, 90, 96, 100, 102, 104, 105, 108, 110, 111, 112, 114, 115, 117, 120, 124, 126, 130, 132, 133, 135, 136, 140, 144, 147, 150, 152, 153, 154, 156, 160, 162, 165 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS If k is a term, then so are all multiples of k. - Robert Israel, Dec 20 2022 LINKS Harvey P. Dale, Table of n, a(n) for n = 1..1000 EXAMPLE 24 is a term since it has two pairs of divisors having an equal sum of digits: 3 and 12; 6 and 24. MAPLE q:= n-> (s-> is(nops(s)>nops({s[]})))(map(x-> add(i, i=convert(x, base, 10)), [numtheory[divisors](n)[]])): select(q, [\$1..165])[]; # Alois P. Heinz, Dec 18 2022 MATHEMATICA a={}; For[k=1, k<=165, k++, If[Length[Intersection[Table[Total[Part[IntegerDigits[Divisors[k]], i]], {i, DivisorSigma[0, k]}]]] < DivisorSigma[0, k], AppendTo[a, k]]]; a tdesQ[n_]:=AnyTrue[Tally[Total[IntegerDigits[#]]&/@Divisors[n]][[All, 2]], #>1&]; Select[ Range[200], tdesQ] (* Harvey P. Dale, Jan 13 2023 *) PROG (Python) from sympy import divisors def sod(n): return sum(map(int, str(n))) def ok(n): s = set() for d in divisors(n, generator=True): sd = sod(d) if sd in s: return True s.add(sd) return False print([k for k in range(166) if ok(k)]) # Michael S. Branicky, Dec 15 2022 (PARI) isok(k) = my(d=divisors(k)); #Set(apply(sumdigits, d)) < #d; \\ Michel Marcus, Dec 19 2022 CROSSREFS Complement of A359075. Cf. A000005, A007953, A359076 (proper divisors). Sequence in context: A031183 A265043 A158871 * A247626 A247627 A327709 Adjacent sequences: A359071 A359072 A359073 * A359075 A359076 A359077 KEYWORD nonn,base AUTHOR Stefano Spezia, Dec 15 2022 STATUS approved

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Last modified November 28 21:44 EST 2023. Contains 367419 sequences. (Running on oeis4.)