

A271676


Prime powers k such that 3k + 4 is a perfect square.


1




OFFSET

1,1


COMMENTS

This sequence is complete. For proof see the link.  Altug Alkan, Apr 15 2016


LINKS

Table of n, a(n) for n=1..4.
Altug Alkan, Proof of Fini and Full


EXAMPLE

4 is in this sequence because 3*4 + 4 = 16 = 4^2,
7 is in this sequence because 3*7 + 4 = 25 = 5^2,
32 is in this sequence because 3*32 + 4 = 100 = 10^2,
64 is in this sequence because 3*64 + 4 = 196 = 14^2.


MATHEMATICA

Select[Range[10^4], PrimePowerQ@ # && IntegerQ@ Sqrt[3 # + 4] &] (* Michael De Vlieger, Apr 12 2016 *)


PROG

(MAGMA) [n: n in [2..10000000]  IsPrimePower(n) and IsSquare(3*n + 4)];
(PARI) lista(nn) = for(n=1, nn, if(isprimepower(n) && issquare(3*n+4), print1(n, ", "))); \\ Altug Alkan, Apr 12 2016


CROSSREFS

Cf. A000961, A271675.
Sequence in context: A283332 A000289 A241426 * A149089 A004031 A243863
Adjacent sequences: A271673 A271674 A271675 * A271677 A271678 A271679


KEYWORD

nonn,fini,full


AUTHOR

JuriStepan Gerasimov, Apr 12 2016


STATUS

approved



