A062045 Positive numbers whose product of digits is 12 times their sum.
666, 1479, 1497, 1568, 1586, 1658, 1685, 1749, 1794, 1856, 1865, 1947, 1974, 2349, 2394, 2439, 2446, 2464, 2493, 2644, 2934, 2943, 3249, 3294, 3345, 3354, 3429, 3435, 3453, 3492, 3534, 3543, 3924, 3942, 4179, 4197, 4239, 4246, 4264, 4293, 4329, 4335, 4353, 4392
Offset: 1
Examples
2349 belongs to the sequence as (2*3*4*9)/(2+3+4+9) = 216/18 = 12.
Links
- Harry J. Smith, Table of n, a(n) for n = 1..500
Crossrefs
Programs
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Mathematica
okQ[n_]:=Module[{idn=IntegerDigits[n]},Times@@idn/Total[idn]==12] Select[Range[10000],okQ] (* Harvey P. Dale, Nov 25 2010 *)
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PARI
isok(n) = my(d=digits(n)); vecprod(d)==12*vecsum(d) \\ Mohammed Yaseen, Sep 12 2022
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Python
from math import prod def ok(n): d = list(map(int, str(n))); return prod(d) == 12*sum(d) print([k for k in range(1, 4400) if ok(k)]) # Michael S. Branicky, Sep 12 2022
Extensions
Corrected and extended by Larry Reeves (larryr(AT)acm.org), Jul 06 2001
More terms from Harvey P. Dale, Nov 25 2010
Offset corrected by Mohammed Yaseen, Sep 12 2022
Comments