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A062036
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Numbers whose product of digits is four times the sum of the digits.
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2
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88, 189, 198, 246, 264, 426, 462, 624, 642, 819, 891, 918, 981, 1247, 1274, 1344, 1427, 1434, 1443, 1472, 1724, 1742, 2147, 2174, 2226, 2262, 2417, 2471, 2622, 2714, 2741, 3144, 3414, 3441, 4127, 4134, 4143, 4172, 4217, 4271, 4314, 4341, 4413, 4431
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,1
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LINKS
| Harry J. Smith, Table of n, a(n) for n=0,...,500
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EXAMPLE
| 1344 belong to the sequence as (1*3*3*4)/(1+3+3+4) =48/12 = 4.
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MATHEMATICA
| p4sQ[n_]:=Module[{idn=IntegerDigits[n]}, Times@@idn/Total[idn]==4]; Select[Range[5000], p4sQ] (* From Harvey P. Dale, Apr 26 2011 *)
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PROG
| (PARI) SumD(x)= { s=0; while (x>9, s=s+x-10*(x\10); x\=10); return(s + x) } ProdD(x)= { p=1; while (x>9, p=p*(x-10*(x\10)); x\=10); return(p*x) } { n=-1; for (m=1, 10^7, if (ProdD(m)==4*SumD(m), write("b062036.txt", n++, " ", m); if (n==500, break)) ) } [From Harry J. Smith (hjsmithh(AT)sbcglobal.net), Jul 30 2009]
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CROSSREFS
| Sequence in context: A043522 A044420 A044801 * A184022 A116448 A046330
Adjacent sequences: A062033 A062034 A062035 * A062037 A062038 A062039
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KEYWORD
| nonn,base,easy
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AUTHOR
| Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Jun 27 2001
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EXTENSIONS
| More terms from Larry Reeves (larryr(AT)acm.org), Jul 06 2001
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