OFFSET
1,2
EXAMPLE
161367245 is in the sequence because sigma(161367245)=1*(6^1)*(3^6)*(7^2)*(4^5).
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}]
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Farideh Firoozbakht, Sep 15 2005
EXTENSIONS
a(11)-a(23) from Donovan Johnson, Sep 16 2009
STATUS
approved