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Positive numbers whose product of digits is three times their sum.
11

%I #26 Jul 31 2022 07:49:51

%S 66,159,167,176,195,235,253,325,333,352,519,523,532,591,617,671,716,

%T 761,915,951,1168,1186,1236,1263,1326,1362,1618,1623,1632,1681,1816,

%U 1861,2136,2163,2316,2361,2613,2631,3126,3162,3216,3261,3612,3621,6118

%N Positive numbers whose product of digits is three times their sum.

%H Harry J. Smith, <a href="/A062035/b062035.txt">Table of n, a(n) for n = 1..500</a>

%e 235 belongs to the sequence as (2*3*5)/(2+3+5) = 30/10 = 3.

%t s3Q[n_]:=Module[{idn=IntegerDigits[n]},3Total[idn]==Times@@idn]; Select[Range[7000],s3Q] (* _Harvey P. Dale_, Mar 20 2011 *)

%o (PARI) isok(n) = my(d=digits(n)); vecprod(d)==3*vecsum(d) \\ _Mohammed Yaseen_, Jul 29 2022

%o (Python)

%o from math import prod

%o def ok(n): d = list(map(int, str(n))); return prod(d) == 3*sum(d)

%o print([k for k in range(1, 7000) if ok(k)]) # _Michael S. Branicky_, Jul 29 2022

%Y Cf. A011540, A034710, A062034, A062036, A062382, A062037, A062384, A062040, A062041, A062043, A062045.

%K nonn,base,easy

%O 1,1

%A _Amarnath Murthy_, Jun 27 2001

%E Corrected and extended by _Harvey P. Dale_ and Larry Reeves (larryr(AT)acm.org), Jul 04 2001

%E Offset corrected by _Mohammed Yaseen_, Jul 29 2022