OFFSET
1,2
COMMENTS
The term a(7) = 120068526 makes use of the convention 0^0 = 1. - Giovanni Resta, Jun 06 2016
EXAMPLE
4461365 is in the sequence because sigma(4461365)=(4^4)*(6^1)*(3^6)*5.
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}]
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Farideh Firoozbakht, Sep 14 2005
EXTENSIONS
a(6)-a(25) from Giovanni Resta, Jun 06 2016
STATUS
approved