

A108022


a(1)=2; a(n) is the smallest prime such that a(n)a(n1) is a 4th power (>0).


1



2, 3, 19, 160019, 1049920019, 1050730019, 1051540019, 12910750019, 13960510019, 14167870019, 67252030019, 67252840019, 67318450019, 196918450019, 197968210019, 568118770019, 568119580019, 938270140019, 938477500019
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OFFSET

1,1


COMMENTS

All members after 19 will end in '0019'.
Also, for n > 3, a(n)  a(n  1) = k^4, k is a multiple of 30.  Zak Seidov, Apr 09 2013


LINKS



EXAMPLE

a(3)=19, for 19 +k^4 to be prime, k must be even and divisible by 5. 19+10^4=10019=43*233,but 19+20^4 is prime.


MATHEMATICA

Join[{2, 3, 19, p=160019}, Table[x=30; While[!PrimeQ[q=p+x^4], x=x+30]; p=q, {19}]] (* Zak Seidov, Apr 09 2013 *)


CROSSREFS



KEYWORD

nonn


AUTHOR



STATUS

approved



