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Search: a199365 -id:a199365
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Numbers n such that 4*n^3 + 1 is prime.
+10
8
1, 3, 4, 7, 9, 10, 19, 25, 34, 37, 39, 42, 49, 54, 55, 72, 73, 78, 85, 87, 93, 94, 102, 108, 109, 118, 138, 142, 147, 157, 160, 165, 168, 175, 192, 195, 202, 210, 214, 220, 228, 232, 243, 247, 249, 250, 252, 253, 258, 267, 273, 274, 279, 289, 297
OFFSET
1,2
COMMENTS
For any n in this sequence, 3*(4*n^3 + 1) has the same nonzero digits as its prime factors in base 2n. - Ely Golden, Dec 12 2016
EXAMPLE
If n=94 then (4*n^3 + 1) = 3322337 (prime).
MATHEMATICA
Select[Range[300], PrimeQ[4*#^3 + 1] &] (* Stefan Steinerberger, Mar 04 2006 *)
PROG
(PARI) is(n)=isprime(4*n^3+1) \\ Charles R Greathouse IV, Feb 17 2017
CROSSREFS
Cf. A001912. See A199307 for the actual primes.
KEYWORD
nonn
AUTHOR
Parthasarathy Nambi, Mar 02 2006
EXTENSIONS
More terms from Stefan Steinerberger, Mar 04 2006
STATUS
approved
Numbers k such that 4k^3 + 3 is prime.
+10
3
0, 1, 5, 10, 14, 20, 28, 34, 38, 49, 55, 59, 61, 80, 98, 103, 118, 133, 145, 146, 154, 160, 185, 196, 206, 224, 229, 241, 245, 250, 251, 320, 325, 334, 376, 383, 385, 388, 398, 416, 418, 440, 451, 454, 475, 476, 481, 488, 490, 493, 496, 500
OFFSET
1,3
COMMENTS
See comment in A199307.
LINKS
MATHEMATICA
Select[Range[0, 3000], PrimeQ[4#^3+3]&] (* Vincenzo Librandi, Aug 01 2012 *)
PROG
(Magma) [n: n in [0..500] | IsPrime(4*n^3+3)]; // Bruno Berselli, Nov 08 2011
(PARI) is(n)=isprime(4*n^3+3) \\ Charles R Greathouse IV, May 22 2017
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, Nov 05 2011
EXTENSIONS
First term added by Vincenzo Librandi, Nov 08 2011
STATUS
approved

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