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A230105 Numbers n such that m + (product of digits of m) = n has exactly one solution m. 4

%I #11 Jan 09 2023 09:06:46

%S 0,2,4,6,8,22,23,24,28,29,30,32,34,35,40,41,42,44,45,46,47,54,55,56,

%T 58,65,66,67,68,75,78,81,85,88,89,90,92,94,95,101,103,105,106,108,112,

%U 114,122,124,125,128,129,132,135,141,143,144,145,146,147,152,154,155,156,158,161,165,166,167,168,175,178,181,185

%N Numbers n such that m + (product of digits of m) = n has exactly one solution m.

%C Numbers n such that A230103(n) = 1.

%H Michael S. Branicky, <a href="/A230105/b230105.txt">Table of n, a(n) for n = 1..10000</a>

%H <a href="/index/Coi#Colombian">Index entries for Colombian or self numbers and related sequences</a>

%o (Python)

%o from math import prod

%o from collections import Counter

%o def b(n): return n + prod(map(int, str(n)))

%o def aupto(n):

%o c = Counter(b(m) for m in range(n+1))

%o return [k for k in range(n+1) if c[k] == 1]

%o print(aupto(185)) # _Michael S. Branicky_, Jan 09 2023

%Y Cf. A230099, A230103, A230104.

%K nonn,base

%O 1,2

%A _N. J. A. Sloane_, Oct 13 2013

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Last modified April 24 14:23 EDT 2024. Contains 371960 sequences. (Running on oeis4.)