OFFSET
1,1
LINKS
Zak Seidov, Table of n, a(n) for n = 1..2000
EXAMPLE
a(1) = 10 because it can be expressed as 2p + 3q in only one way, 2 * 2 + 3 * 2, and is the smallest integer for which this is the case.
a(2) = 19 because it can be expressed as 2p + 3q in only two ways, 2 * 2 + 3 * 5 = 2 * 5 + 3 * 3, and is the smallest integer for which this is the case.
MATHEMATICA
mx = 10000; s = Table[0, {mx}]; Do[a = 2 Prime[i] + 3 Prime[k]; s[[a]]++, {k, PrimePi[(mx - 4)/3]}, {i, PrimePi[(mx - 3 Prime[k])/2]}]; Table[Position[s, n][[1, 1]], {n, 50}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Zak Seidov, Dec 02 2012
STATUS
approved