A308472 Numbers that are divisible by the sum of the digits of the product of their digits.
1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 12, 15, 24, 25, 28, 36, 52, 54, 63, 99, 111, 112, 115, 125, 126, 132, 138, 152, 154, 156, 162, 165, 168, 182, 187, 189, 198, 212, 215, 216, 224, 234, 251, 252, 255, 261, 264, 276, 279, 297, 312, 318, 324, 333, 342, 354, 369, 372, 396, 432, 441
Offset: 1
Examples
2771 is a term of this sequence because 2*7*7*1 = 98 --> 9 + 8 = 17 --> 2771 / 17 = 163.
Links
- David Consiglio, Jr., Table of n, a(n) for n = 1..6253
Programs
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Magma
[n:n in [1..450]| not 0 in Intseq(n) and IsIntegral(n/(&+Intseq((&*(Intseq(n))))))]; // Marius A. Burtea, May 31 2019
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Maple
d:= n-> convert(n, base, 10): q:= n-> (m-> m>0 and irem(n, add(j, j=d(m)))=0)(mul(i, i=d(n))): select(q, [$1..500])[]; # Alois P. Heinz, May 29 2019
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Mathematica
Select[Range[500],DigitCount[#,10,0]==0&&Divisible[#,Total[ IntegerDigits[ Times@@IntegerDigits[#]]]]&] (* Harvey P. Dale, Jan 24 2021 *)
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PARI
spd(n) = my(d=digits(n)); sumdigits(vecprod(d)); \\ A128212 isok(n) = my(p=spd(n)); p && (n % p == 0); \\ Michel Marcus, May 29 2019
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Python
def dprod(n): x = str(n) start = 1 for q in x: start *= int(q) return start def dsum(n): x = str(n) start = 0 for q in x: start += int(q) return start seq_1 = [n for n in range(1,10000) if dprod(n) != 0 and n % (dsum(dprod(n))) == 0] print(seq_1)
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