A114229 Smallest number m such that A114228(m) = n.

2, 3, 34, 10, 47, 20, 46, 52, 221, 462, 92, 77, 619, 94, 319, 2176, 263, 154, 700, 1980, 1336, 928, 2477, 3243, 428, 461, 2146, 4224, 1456, 2735, 3373, 5319, 6439, 4522, 4508, 4516, 11073, 1814, 9940, 10746, 17523, 6680, 16409, 10023, 16107, 14289

Offset: 1

Author

Lei Zhou, Nov 18 2005

Keywords

• nonn

Comments

Sequence is defined for all n>=1.

A114228(a(n)) = n and A114228(m) <> n for m < a(n).

Crossrefs

Cf. A114228, A114227.

Programs

Haskell

import Data.List (elemIndex); import Data.Maybe (fromJust)
a114229 = (+ 2) . fromJust . (`elemIndex` (map a114228 [2..]))
-- Reinhard Zumkeller, Oct 31 2013

Mathematica

Do[ns[k] = 0, {k, 1, 2000}]; n2 = 0; n1 = 1; While[n2 <= 200, n1++; p1 = Prime[n1]; n2 = 1; p2 = 2; While[cp = p1 + 2*p2; ! PrimeQ[cp], n2++; p2 = Prime[n2]]; If[ns[n2] == 0, ns[n2] = n1; Print[n2, "[", n1, "]"]]]; Table[ns[k], {k, 1, n2}]

Extensions

Edited definition to conform to OEIS style. - Reinhard Zumkeller, Oct 31 2013