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

1,3

Links

Table of n, a(n) for n=1..47.

Example

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

Mathematica

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

Prog

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

Crossrefs

Cf. A003132, A029793, A249515.

Sequence in context: A214472 A259379 A122475 * A252805 A089256 A112136

Adjacent sequences: A383325 A383326 A383327 * A383329 A383330 A383331

Keyword

nonn,base

Author

Jean-Marc Rebert, Apr 23 2025

Status

approved