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A291206 Semi-octavan primes: primes of the form x^4 + y^8. 2
2, 17, 257, 337, 881, 1297, 2657, 6577, 10657, 14897, 16561, 28817, 65537, 65617, 66161, 80177, 83777, 149057, 160001, 166561, 260017, 280097, 331777, 391921, 394721, 411361, 463537, 596977, 614657, 621217, 847601 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Charles R Greathouse IV, Table of n, a(n) for n = 1..10000

A. J. C. Cunningham, High quartan factorisations and primes, Messenger of Mathematics 36 (1907), pp. 145-174.

EXAMPLE

a(1) = 1^4 + 1^8 = 2.

a(2) = 2^4 + 1^8 = 17.

a(3) = 1^4 + 2^8 = 257.

a(4) = 3^4 + 2^8 = 337.

PROG

(PARI) list(lim)=my(v=List([2]), x4, t); for(x=1, sqrtnint(lim\=1, 4), x4=x^4; forstep(y=x%2+1, sqrtnint(lim-x4, 8), 2, if(isprime(t=x4+y^8), listput(v, t)))); Set(v)

CROSSREFS

Subsequence of A002645. A006686 is a subsequence.

Cf. A028916.

Sequence in context: A253549 A002590 A029735 * A037896 A099714 A195443

Adjacent sequences:  A291203 A291204 A291205 * A291207 A291208 A291209

KEYWORD

nonn

AUTHOR

Charles R Greathouse IV, Aug 21 2017

STATUS

approved

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Last modified February 22 15:12 EST 2018. Contains 299454 sequences. (Running on oeis4.)