A073320 A073259(n)=3: the length of iteration transient leading to n-th composite number equals 3.

4, 5, 8, 9, 13, 16, 17, 18, 22, 23, 24, 27, 31, 35, 36, 40, 41, 46, 47, 56, 64, 69, 70, 71, 89, 90, 91, 92, 93, 94, 95, 103, 109, 110, 111, 112, 113, 146, 147, 161, 162, 163, 171, 172, 173, 174, 196, 240, 241, 242, 243, 261, 262, 263, 277, 438, 439, 440, 1137, 1138

Offset: 1

Author

Labos Elemer, Jul 29 2002

Keywords

• fini
• full
• nonn

Examples

			The sequence is most probably complete. a(1)=4: the fixed point list from m=a(1) to composite[m] is: {4,7,9}, the length is 3; last term is a(64)=1142 with transient list {1142,1332,1360}.
		

Crossrefs

Cf. A002808, A073259.

Programs

Mathematica

lfp[x_] := Length[FixedPointList[x+PrimePi[ # ]+1&, x]]-1 Do[s=lfp[n]; If[Equal[s, 3], Print[n]], {n, 1, 10000000}]

Formula

See Program.