

A169583


nth prime*87 is the square of a prime.


1



1, 4, 12, 19, 47, 59, 115, 167, 217, 251, 306, 348, 414, 618, 630, 662, 809, 1077, 1138, 1218, 1670, 1876, 2272, 2680, 2869, 3402, 3633, 4242, 4353, 4661, 5255, 6463, 6596, 6986, 8543, 8870, 8992, 9340, 9444, 10265, 11544, 11921, 12449, 13887, 14031
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OFFSET

1,2


LINKS

Harvey P. Dale, Table of n, a(n) for n = 1..350


EXAMPLE

1 is in the sequence because 1st prime*87=(2nd prime)^2;
4 is in the sequence because 4th prime*87=(4th prime)^2;
12 is in the sequence because 12th prime*87=(7th prime)^2.


MATHEMATICA

Select[Range[15000], PrimeQ[Sqrt[8Prime[#]7]]&] (* Harvey P. Dale, Nov 10 2017 *)


PROG

(PARI) isok(n) = issquare(sq=prime(n)*87) && isprime(sqrtint(sq)); \\ Michel Marcus, Apr 15 2014


CROSSREFS

Cf. A000040, A001248, A055469, A118940.
Sequence in context: A301230 A304474 A301068 * A239727 A341888 A009557
Adjacent sequences: A169580 A169581 A169582 * A169584 A169585 A169586


KEYWORD

nonn


AUTHOR

JuriStepan Gerasimov, Mar 01 2010


EXTENSIONS

Corrected (1077 inserted) and extended by R. J. Mathar, Jun 04 2010


STATUS

approved



