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A214935 Index of the primes of A205827, A000720(A205827(n)). 9
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 (list; graph; refs; listen; history; text; internal format)
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: A229686 A208965 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

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Last modified August 14 21:07 EDT 2018. Contains 313756 sequences. (Running on oeis4.)