

A248346


Primes of the form 2^x  y^2, with y^2 < 2^x.


2



2, 3, 7, 23, 31, 47, 71, 79, 103, 127, 151, 199, 223, 271, 367, 431, 463, 487, 503, 727, 751, 823, 967, 1087, 1303, 1319, 1423, 1439, 1559, 1607, 1759, 1823, 1879, 1951, 1999, 2039, 2143, 3343, 3527, 3623, 3967, 4447, 4943, 5167, 5503, 5591, 5791, 6199, 6343
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,1


COMMENTS

Primes in A051213.


LINKS

Table of n, a(n) for n=1..49.


EXAMPLE

7 is in this sequence because 7 = 2^3  1^2 = 2^4  3^2 = 2^5  5^2 = 2^7  11^2 = 2^15  181^2.
1559 is in this sequence because 1559 = 2^19  723^2 is prime.  Sean A. Irvine, Apr 28 2022


MATHEMATICA

Select[Union[Flatten[Table[2^x  y^2, {x, 16}, {y, 0, Floor[Sqrt[2^x]]}]]], PrimeQ] (* Alonso del Arte, Oct 05 2014 *)


CROSSREFS

Cf. A038198, A051213, A060728, A248344.
Primes in A056007 form a subset of the numbers in this sequence.
Sequence in context: A120302 A093363 A291525 * A236514 A211997 A127581
Adjacent sequences: A248343 A248344 A248345 * A248347 A248348 A248349


KEYWORD

nonn


AUTHOR

JuriStepan Gerasimov, Oct 05 2014


EXTENSIONS

a(24)a(38) from Alonso del Arte, Oct 05 2014
More terms and missing terms inserted by Sean A. Irvine, Apr 28 2022


STATUS

approved



