A214935 Index of the primes of A205827, A000720(A205827(n)).

1, 2, 4, 9, 30, 189, 217, 2225, 3385, 14357, 30802, 31545, 104071, 149689, 1094421, 1319945, 10655462, 23163298, 112228683, 182837804, 203615628, 486570087, 1094330259, 11992433550, 17883926781, 50070452577, 52302956123, 72178455400

Offset: 1

Author

John W. Nicholson, Oct 28 2012

Keywords

• nonn

Comments

A000040(a(n)) = A205827(n).

With pi(x) being the prime counting function, A000720(x), for n from 1 to 3, a(n) = pi(A111870(n)) = A241542(n), for n from 5 to 28, a(n) = pi(A111870(n-1)) = A241542(n-1). - John W. Nicholson, May 10 2014

Examples

			a(4) = 9, A000040(9) = 23, and A205827(4) = 23.
		

Links

• John W. Nicholson, Table of n, a(n) for n = 1..38

Crossrefs

Cf. A205827.

Programs

PARI

record=0;i=0;A214935=vectorsmall(38);for(n=1,75,current=(A000101[n]/A002386[n]*1.)^A005669[n];if(current>record,record=current;i++;A214935[i]=A005669[n]))

Formula

a(n) = pi(A205827(n)) = A000720(A205827(n)).

Extensions

a(13)-a(28) from Donovan Johnson, Oct 28 2012

a(29)-a(38) from John W. Nicholson, Dec 01 2013