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A094493 Primes p such that 2^j+p^j are primes for j=0,1,2,16. 0
43577, 84317, 93887, 108377, 124247, 346667, 379997, 431867, 461297, 579197, 681257, 819317, 863867, 889037, 1143047, 1146797, 1271027, 1306817, 1518707, 1775867, 1926647, 1948517, 2119937, 2177447, 2348807, 2491607, 2604557 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Primes of 2^j+p^j form are a generalization of Fermat-primes. 1^j is replaced by p^j. This is strongly supported by the observation that corresponding j-exponents are apparently powers of 2 like for the 5 known Fermat primes. See A094473-A094491.

LINKS

Table of n, a(n) for n=1..27.

EXAMPLE

For j=0: 1+1=2 is prime; other conditions are:

because of p^1+2=prime; 3rd and 4th conditions are as

follows: prime=p^2+4 and prime=65536+p^16.

MATHEMATICA

{ta=Table[0, {100}], u=1}; Do[s0=2; s1=2+Prime[j]^1; s2=4+Prime[j]^2; s16=65536+Prime[j]^16 If[PrimeQ[s0]&&PrimeQ[s1]&&PrimeQ[s2]&&PrimeQ[s16], Print[{j, Prime[j]}]; ta[[u]]=Prime[j]; u=u+1], {j, 1, 1000000}]

Select[Prime[Range[2*10^5]], AllTrue[Table[2^k+#^k, {k, {0, 1, 2, 16}}], PrimeQ]&] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Jun 05 2021 *)

CROSSREFS

Cf. A082101, A094473-A094491.

Sequence in context: A233690 A205923 A251995 * A342580 A165479 A140931

Adjacent sequences:  A094490 A094491 A094492 * A094494 A094495 A094496

KEYWORD

nonn,changed

AUTHOR

Labos Elemer, Jun 01 2004

STATUS

approved

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Last modified June 14 16:56 EDT 2021. Contains 345037 sequences. (Running on oeis4.)