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Search: id:A034710
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| A034710 |
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Positive numbers for which the sum of digits equals the product of digits. |
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+0
13
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| 1, 2, 3, 4, 5, 6, 7, 8, 9, 22, 123, 132, 213, 231, 312, 321, 1124, 1142, 1214, 1241, 1412, 1421, 2114, 2141, 2411, 4112, 4121, 4211, 11125, 11133, 11152, 11215, 11222, 11251, 11313, 11331, 11512, 11521, 12115, 12122, 12151, 12212, 12221, 12511
(list; graph; listen)
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OFFSET
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1,2
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COMMENT
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Positive numbers n such that A007953(n) = A007954(n).
If n is a member, the digits of n are solutions of the equation x1*x2*...*xr = x1+x2+...+xr ; xi are from [1...9]. Permutations of digits (x1,...,xr) are different numbers n with the same property S(n)=PI(n). For example : x1*x2=x1+x2 this equation has only 1 solution (2,2) which gives the number 22. x1*x2*x3=x1+x2+x3 has a solution (1,2,3), so numbers 123,132,213,231,312,321 has the property. - Ctibor O. Zizka (ctibor.zizka(AT)seznam.cz), Mar 04 2008
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LINKS
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T. D. Noe, Table of n, a(n) for n=1..1200
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EXAMPLE
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1124 is a member since 1+1+2+4 = 1*1*2*4 = 8.
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MATHEMATICA
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Select[Range[12512], (Plus @@ IntegerDigits[ # ]) == (Times @@ IntegerDigits[ # ]) &] (Alonso Delarte (alonso.delarte(AT)gmail.com), May 16 2005)
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CROSSREFS
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Cf. A061672.
Sequence in context: A110002 A064158 A064702 this_sequence A061672 A132080 A048386
Adjacent sequences: A034707 A034708 A034709 this_sequence A034711 A034712 A034713
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KEYWORD
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nonn,base,nice,easy
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AUTHOR
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Erich Friedman (erich.friedman(AT)stetson.edu)
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EXTENSIONS
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Corrected by Larry Reeves (larryr(AT)acm.org), Jun 27 2001
Definition changed by njas to specifically exclude 0, Sep 22 2007
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