A022450 a(1) = 2; a(n+1) = a(n)-th composite.

2, 6, 12, 21, 33, 49, 69, 94, 125, 164, 212, 270, 339, 422, 520, 636, 774, 933, 1121, 1339, 1590, 1880, 2210, 2587, 3021, 3512, 4074, 4710, 5427, 6239, 7155, 8183, 9339, 10637, 12084, 13705, 15517, 17534, 19773, 22266, 25030, 28095, 31484, 35239, 39387, 43960

Offset: 1

Author

Clark Kimberling

Keywords

• nonn

References

• C. Kimberling, Fractal sequences and interspersions, Ars Combinatoria, vol. 45 p 157 1997.

Links

• Chai Wah Wu, Table of n, a(n) for n = 1..900
• C. Kimberling, Interspersions

Crossrefs

Cf. A006508, A022451, A025010, A025011.

Programs

Mathematica

g[ n_Integer ] := (k = n + PrimePi[ n ] + 1; While[ k - PrimePi[ k ] - 1, k++ ]; k); NestList[ g, 2, 45 ]
With[{cmps=Select[Range[100000],CompositeQ]},NestList[cmps[[#]]&,2,50]] (* Harvey P. Dale, Jun 24 2025 *)