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A112016
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Numbers n with odd length such that sigma(n) = d_1*(d_2^d_3) *...*(d_(k-1)^d_k) where d_1 d_2 ... d_k is the decimal expansion of n.
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3
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1, 127, 1443572, 2859151, 5272635, 5469390, 5668072, 9662421, 121734535, 124825592, 161367245, 168215370, 185335291, 211254594, 217299630, 225624553, 236125265, 251716960, 271374710, 272433643, 291732835, 292536521, 345267332
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,2
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EXAMPLE
| 161367245 is in the sequence because sigma(161367245)=1*(6^1)*(3^6)*(7^2)*(4^5).
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MATHEMATICA
| Do[h = IntegerDigits[n]; k = Length[h]; If[OddQ[k] && Select[Range[k/2], h[[2# ]] == 0 ==h[[2#+1]] &] == {}&& DivisorSigma[1, n] == h[[1]]*Product[h[[2j]]^h[[2j+1]], {j, k/2}], Print[n]], {n, 162000000}]
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CROSSREFS
| Cf. A112014, A112015.
Sequence in context: A175825 A195218 A135813 * A135982 A135983 A101327
Adjacent sequences: A112013 A112014 A112015 * A112017 A112018 A112019
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KEYWORD
| base,nonn
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AUTHOR
| Farideh Firoozbakht (mymontain(AT)yahoo.com), Sep 15 2005
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EXTENSIONS
| a(11)-a(23) from Donovan Johnson (donovan.johnson(AT)yahoo.com), Sep 16 2009
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