A073168 a(n) = A007821(n) - A022449(n).

1, 5, 9, 9, 9, 15, 16, 17, 18, 17, 25, 19, 21, 27, 31, 26, 21, 22, 21, 35, 38, 31, 35, 31, 34, 33, 37, 39, 49, 49, 33, 52, 49, 47, 39, 43, 47, 47, 48, 48, 41, 49, 48, 60, 59, 59, 49, 52, 58, 58, 63, 71, 75, 65, 65, 67, 71, 79, 75, 81, 84, 77, 65, 69, 72, 72, 67, 69, 61, 65, 65

Offset: 1

Author

Labos Elemer, Jul 19 2002

Keywords

• nonn

Comments

Values of commutator of A000040 and A002808 functions i.e., of prime() and composite().

Crossrefs

Cf. A000040, A002808, A007821, A022449.

Programs

Mathematica

c[n_Integer] := FixedPoint[n+PrimePi[ # ]+1&, n] Table[Prime[c[w]]-c[Prime[w]], {w, 1, 10000}];