A161913 Numbers k such that A001223(k) <> A000005(k).

4, 9, 10, 11, 12, 15, 16, 19, 20, 21, 23, 25, 26, 28, 29, 30, 31, 33, 34, 35, 36, 37, 39, 40, 42, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 77, 78

Offset: 1

Author

Omar E. Pol, Jul 04 2009

Keywords

• easy
• nonn

Links

• Nathaniel Johnston, Table of n, a(n) for n = 1..10000
• Omar E. Pol, Illustration: Divisors and pi(x)

Crossrefs

Cf. A000005, A001223, A068526, A161911, A161912, A162188, A162189.

Programs

Maple

p2:=2:for n from 1 to 78 do p1:=p2:p2:=ithprime(n+1):if(p2-p1<>tau(n))then print(n);fi:od: # Nathaniel Johnston, Apr 15 2011