

A109215


Smallest factor of 3^(2n)+(2n)^3.


1



17, 5, 3, 11, 11, 3, 677, 17, 3, 83, 23, 3, 5, 29, 3, 1049, 23, 3, 307, 41, 3, 5, 5, 3, 41, 53, 3, 523347633027360537213687137, 59, 3, 11, 5, 3, 227, 71, 3, 630023, 101, 3, 29, 47, 3, 5, 89, 3, 1957243, 11, 3, 251, 101, 3, 5, 5, 3, 29, 113, 3, 1289, 11, 3, 701, 5, 3, 307
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OFFSET

1,1


COMMENTS

For n=1 and 28 we have the only two known cases where 3^(2n)+(2n)^3 is prime: 17 and 523347633027360537213687137. Cases n=3*m are trivial and may be omitted.
There are no further cases when 3^(2n)+(2n)^3 is prime up to n = 3500. Hugo Pfoertner, Jun 25 2005
n = 5056 gives a probable prime. Hans Havermann, Jun 24 2005


LINKS

Table of n, a(n) for n=1..64.


MATHEMATICA

Table[With[{k=3}, FactorInteger[n^k+k^n]][[1, 1]], {n, 2, 100, 2}]


CROSSREFS

Cf. A109216.
Sequence in context: A070718 A040277 A196924 * A254070 A297982 A298631
Adjacent sequences: A109212 A109213 A109214 * A109216 A109217 A109218


KEYWORD

base,nonn


AUTHOR

Zak Seidov, Jun 24 2005


EXTENSIONS

More terms from Robert G. Wilson v, Jun 25 2005


STATUS

approved



