A249728 After a(1) = 1 each n appears A000720(n) times.

1, 2, 3, 3, 4, 4, 5, 5, 5, 6, 6, 6, 7, 7, 7, 7, 8, 8, 8, 8, 9, 9, 9, 9, 10, 10, 10, 10, 11, 11, 11, 11, 11, 12, 12, 12, 12, 12, 13, 13, 13, 13, 13, 13, 14, 14, 14, 14, 14, 14, 15, 15, 15, 15, 15, 15, 16, 16, 16, 16, 16, 16, 17, 17, 17, 17, 17, 17, 17, 18, 18, 18, 18, 18, 18, 18, 19, 19, 19, 19, 19, 19, 19, 19, 20, 20, 20, 20, 20, 20, 20, 20

Offset: 1

Author

Antti Karttunen, Nov 06 2014

Keywords

• nonn

Links

• Antti Karttunen, Table of n, a(n) for n = 1..10016

Crossrefs

Cf. A000720, A046992, A249727, A249809.

Programs

Mathematica

Join[{1},Table[Table[n,PrimePi[n]],{n,20}]//Flatten] (* Harvey P. Dale, Nov 24 2018 *)