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A211389
a(n) is the first occurrence of n in sequence A209266.
0
3, 5, 9, 14, 16, 26, 54, 67, 74, 103, 161, 293, 236, 432, 249, 788, 1078, 796, 1885, 2091, 1712, 2618, 4099, 7088, 8137, 8091, 16086, 12595, 27627, 22835, 44576, 31305, 68888, 109617, 86463, 77206, 126383, 202035
OFFSET
1,1
EXAMPLE
A209266 = {0, 0, 1, 1, 2, 2, 2, 1, 3, 3, 1, 3, 3, 4, 3, 5, 4, 2, 5, 4, 4, 4, 4, 3, 3, 6, 6, 4,...}.
Number 1 first appears as A209266(3), number 2 as A209266(5), number 3 as A209266(9)...
So, a = {3, 5, 9, ...} starting from a(1)=3.
MATHEMATICA
aim = 32; a = Table[0, {i, 1, aim}]; zeros = aim; i = 2; While[i++; p = Prime[i]; ct = 0; Do[If[(PrimeQ[p - j]) && (PrimeQ[p + j]), f = Last[FactorInteger[j]][[1]]; If[f <= 5, ct++]], {j, 2, p, 2}]; If[(ct <= aim) && (a[[ct]] == 0), a[[ct]] = i; zeros--; zeros > 0]; a
CROSSREFS
Cf. A209266.
Sequence in context: A146433 A134672 A321024 * A335193 A288259 A355489
KEYWORD
nonn,hard
AUTHOR
Lei Zhou, Feb 07 2013
STATUS
approved