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A249334
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Numbers n for which the digital sum contains the same distinct digits as the digital product.
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7
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0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 22, 99, 123, 132, 213, 231, 312, 321, 1124, 1137, 1142, 1173, 1214, 1241, 1317, 1371, 1412, 1421, 1713, 1731, 2114, 2141, 2411, 3117, 3171, 3344, 3434, 3443, 3711, 4112, 4121, 4211, 4334, 4343, 4433, 7113, 7131, 7311, 11125, 11133
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OFFSET
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1,3
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COMMENTS
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Numbers n such that A007953(n) contains the same distinct digits as A007954(n). (But either of the two may contain some digit(s) more than once.)
Supersequence of A034710 (positive numbers for which the sum of digits is equal to the product of digits).
The sequence is infinite since, e.g., A002275(n) = (10^n-1)/9 is in the sequence for all n = A002275(k), k>=0; and more generally N(k,d) = A002275(n)-1+d with n = (A002275(k)-1)*d+1, k>0 and 0<d<10 (with n digits which sum to n-1+d = (10^k-1)/9*d). - M. F. Hasler, Oct 29 2014
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LINKS
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EXAMPLE
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1137 is a member since 1+1+3+7 = 12 and 1*1*3*7 = 21.
3344 is in this list because 3+3+4+4=14 has the same (distinct) digits as 3*3*4*4=144.
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PROG
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(Magma) [n: n in [1..10^6] | Set(Intseq(&*Intseq(n))) eq Set(Intseq(&+Intseq(n)))]
(PARI) is_A249334(n)=Set(digits(sumdigits(n)))==Set(digits(prod(i=1, #n=digits(n), n[i]))) \\ M. F. Hasler, Oct 29 2014
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CROSSREFS
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KEYWORD
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nonn,base
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AUTHOR
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STATUS
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approved
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