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A112015
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Numbers n with odd length such that sigma(n) = (d_1^d_2)*(d_3^d_4) *...*(d_(k-2)^d_(k-1))*d_k where d_1 d_2 ... d_k is the decimal expansion of n.
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2
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OFFSET
| 1,2
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COMMENTS
| There is no further term up to 10^7.
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EXAMPLE
| 4461365 is in the sequence because sigma(4461365)=(4^4)*(6^1)*(3^6)*5.
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MATHEMATICA
| Do[h=IntegerDigits[n]; k=Length[h]; If[h[[k]] != 0 && OddQ[k] && Select[Range[k/2], h[[2#-1]] == 0 ==h[[2# ]] &] == {} && DivisorSigma[1, n] == h[[k]]*Product[h[[2j-1]]^h[[2j]], {j, k/2}], Print[n]], {n, 10^7}]
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CROSSREFS
| Cf. A112014, A112016.
Sequence in context: A186061 A204395 A181261 * A128879 A203258 A089009
Adjacent sequences: A112012 A112013 A112014 * A112016 A112017 A112018
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KEYWORD
| base,more,nonn
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AUTHOR
| Farideh Firoozbakht (mymontain(AT)yahoo.com), Sep 14 2005
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