

A086122


Primes of the form (5^k1)/4.


7



31, 19531, 12207031, 305175781, 177635683940025046467781066894531, 14693679385278593849609206715278070972733319459651094018859396328480215743184089660644531, 35032461608120426773093239582247903282006548546912894293926707097244777067146515037165954709053039550781
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,1


COMMENTS

Corresponding exponents k are listed in A004061.  Alexander Adamchuk, Jan 23 2007


LINKS

Table of n, a(n) for n=1..7.


FORMULA

a(n) = (5^A004061(n)  1)/4 = A003463[ A004061(n) ].  Alexander Adamchuk, Jan 23 2007
A003464 INTERSECT A000040.


MATHEMATICA

Do[f=(5^n1)/4; If[PrimeQ[f], Print[{n, f}]], {n, 1, 1000}] (* Alexander Adamchuk, Jan 23 2007 *)
Select[(5^Range[300]1)/4, PrimeQ] (* Harvey P. Dale, Dec 11 2016 *)


CROSSREFS

Cf. A000668, A076481.
Cf. A003463, A004061, A074479.
Sequence in context: A161395 A215610 A292009 * A239167 A263585 A176349
Adjacent sequences: A086119 A086120 A086121 * A086123 A086124 A086125


KEYWORD

nonn


AUTHOR

Labos Elemer, Jul 23 2003


EXTENSIONS

More terms from Alexander Adamchuk, Jan 23 2007


STATUS

approved



