OFFSET
0,1
COMMENTS
Theorem: Except for 24, the sequence is the union of primes and 6*primes.
EXAMPLE
Any prime p, since it has semiperimeter p+1 and its integer log is p.
MATHEMATICA
logint = Function[n, Module[{vn}, vn = Transpose[FactorInteger[n]]; vn[[1]].vn[[2]] ]]; semiperi = Function[n, Min[Divisors[n] + Reverse[Divisors[n]]]]; sq = {}; Do[If[semiperi[k] == logint[k] + 1, AppendTo[sq, k]], {k, 2, 500}]; sq
CROSSREFS
KEYWORD
nonn
AUTHOR
Carlos Alves, Dec 31 2004
STATUS
approved