A383328 Numbers that have the same set of digits as the sum of the squares of their digits.

0, 1, 155, 224, 242, 334, 343, 422, 433, 505, 515, 550, 551, 1388, 1788, 1838, 1878, 1883, 1887, 3188, 3334, 3336, 3343, 3363, 3433, 3633, 3818, 3881, 4333, 5005, 5050, 5500, 6333, 7188, 7818, 7881, 8138, 8178, 8183, 8187, 8318, 8381, 8718, 8781, 8813, 8817, 8831

Offset: 1

Author

Jean-Marc Rebert, Apr 23 2025

Keywords

• nonn
• base

Examples

			155 and 1^2 + 5^2 + 5^2 = 51 have the same set of digits {1,5}, so 155 is a term.
		

Crossrefs

Cf. A003132, A029793, A249515.

Programs

Mathematica

q[k_] := Module[{d = IntegerDigits[k]}, Union[d] == Union[IntegerDigits[Total[d^2]]]]; Select[Range[0, 10000], q] (* Amiram Eldar, Apr 23 2025 *)

PARI

isok(k) = my(d=digits(k)); Set(d) == Set(digits(sum(i=1, #d, d[i]^2))); \\ Michel Marcus, May 13 2025

Python

def ok(n): return set(s:=str(n)) == set(str(sum(int(d)**2 for d in s)))
print([k for k in range(10**4) if ok(k)]) # Michael S. Branicky, Apr 23 2025