OFFSET
0,1
COMMENTS
a(0) .. a(29) are in the list; additional know values are a(34) = 746130, a(35) = 903210, a(36) = 570570, a(40) = 510510, a(41) = 690690 and a(46) = 870870. If n in { 30, 31, 32, 33, 37, 38, 39, 42, 43, 44, 45}, or if n > 46, then a(n) > 10^6.
a(258) > 10^11. - Donovan Johnson, Oct 15 2013
LINKS
T. D. Noe and Donovan Johnson, Table of n, a(n) for n = 0..257 (terms up to a(90) from T. D. Noe)
M. Engelhardt, Number of Primes arising as Sum of a Factorization.
EXAMPLE
Sequence A088627 starts with 1,1,2,0, meaning that 2 and 4 yield 1 prime, 6 yields 2 and 8 yields 0 primes; therefore a(0) = 8, a(1) = 2 and a(2) = 6.
MATHEMATICA
DivPrimes[n_Integer] := Length[Select[Union[Divisors[n]+Reverse[Divisors[n]]], PrimeQ]]; nn=40; t=Table[0, {nn}]; cnt=0; k=0; While[cnt<nn, k=k+2; m=DivPrimes[k]; If[0<m<=nn && t[[m]]==0, t[[m]]=k; cnt++ ]]; Prepend[t, 8] [From T. D. Noe, Aug 02 2010]
PROG
(Java) // Programs available from Matthias Engelhardt.
CROSSREFS
KEYWORD
nonn
AUTHOR
Matthias Engelhardt, Jan 05 2004
EXTENSIONS
Extended by T. D. Noe, Aug 02 2010
STATUS
approved