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A212430 Numbers n such that n and n^4 are sums of two twin primes. 1
384, 840, 8676, 33300, 34980, 37044, 39984, 42024, 50604, 53760, 55056, 61680, 64380, 71064, 83520, 88176, 97644, 103740, 120204, 129840, 133896, 148764, 154524, 160416, 168120, 173064, 184800, 188880, 199056, 207984, 234744, 266640, 292116, 307044, 356184 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

All terms are multiples of 12.

LINKS

Harvey P. Dale, Table of n, a(n) for n = 1..1000

FORMULA

n/2 +/-1 and (n^4)/2 +/- 1 are primes.

EXAMPLE

384=191+193, 384^3=147456=73727+73729.

MATHEMATICA

Select[12 Range[30000], AllTrue[{#/2+1, #/2-1, #^4/2+1, #^4/2-1}, PrimeQ]&] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Feb 01 2017 *)

PROG

(PARI) isok(n) = !(n % 2) && isprime(n/2-1) && isprime(n/2+1) && isprime(n^4/2-1) && isprime(n^4/2+1); \\ Michel Marcus, Oct 19 2013

CROSSREFS

Cf. A001043, A074924, A213784, A213789, A213811.

Sequence in context: A046492 A110296 A179664 * A134175 A233886 A256735

Adjacent sequences:  A212427 A212428 A212429 * A212431 A212432 A212433

KEYWORD

nonn

AUTHOR

Zak Seidov, Jun 21 2012

STATUS

approved

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Last modified February 22 10:16 EST 2019. Contains 320390 sequences. (Running on oeis4.)