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

1,2

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

Links

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

Formula

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

Example

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

Prog

(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]))

Crossrefs

Cf. A205827.

Sequence in context: A208965 A306505 A243789 * A092329 A053548 A054119

Adjacent sequences: A214932 A214933 A214934 * A214936 A214937 A214938

Keyword

nonn

Author

John W. Nicholson, Oct 28 2012

Extensions

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

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

Status

approved