A022798 a(n) = P(n) + c(n), where P(1) = 1, P(n) = (n-1)-st prime for n >= 2, c(n) = n-th number not in sequence P.

5, 8, 11, 14, 17, 23, 27, 32, 35, 41, 49, 52, 59, 65, 68, 73, 80, 87, 91, 99, 104, 107, 114, 119, 127, 136, 141, 145, 151, 154, 159, 175, 180, 187, 190, 201, 205, 212, 219, 224, 231, 239, 243, 254, 257, 262, 265, 279, 292, 297, 301, 307, 314, 317

Offset

1,1

Links

Paolo Xausa, Table of n, a(n) for n = 1..10000

Formula

a(n) = n-th composite + n-th noncomposite = A002808(n) + A008578(n). - Jaroslav Krizek, Nov 18 2009

Mathematica

With[{c=Select[Range[100], CompositeQ]}, c+Join[{1}, Prime[Range[Length[c]-1]]]] (* Paolo Xausa, Nov 03 2023 *)

Crossrefs

Cf. A002808, A008578.

Sequence in context: A180486 A314387 A314388 * A022808 A104279 A184919

Adjacent sequences: A022795 A022796 A022797 * A022799 A022800 A022801

Keyword

nonn

Author

Clark Kimberling

Extensions

Wrong formula removed by Paolo Xausa, Nov 03 2023

Status

approved