A002649 Quintan primes: p = (x^5 - y^5)/(x - y). (Formerly M3964 N1636)

5, 31, 211, 1031, 2801, 4651, 5261, 6841, 8431, 14251, 17891, 20101, 21121, 22621, 22861, 26321, 30941, 33751, 36061, 41141, 46021, 48871, 51001, 58411, 61051, 88741, 92821, 103801, 109141, 114641, 118061, 125591, 170101, 176641, 209801

Offset

1,1

Comments

5 is a term because x^4 + y*x^3 + y^2*x^2 + y^3*x + y^4 = 5 when x=y=1. - N. J. A. Sloane, May 12 2014

References

A. J. C. Cunningham, Binomial Factorisations, Vols. 1-9, Hodgson, London, 1923-1929; see Vol. 2, p. 200.

N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Links

Jens Kruse Andersen, Table of n, a(n) for n = 1..10000

A. J. C. Cunningham, Binomial Factorisations, Vols. 1-9, Hodgson, London, 1923-1929. [Annotated scans of a few pages from Volumes 1 and 2]

Prog

(PARI) m=10^6; v=[5]; for(x=1, m^(1/4), for(y=1, x-1, n=(x^5-y^5)/(x-y); if(n<=m && isprime(n), v=concat(v, n)))); vecsort(v) \\ Jens Kruse Andersen, Jul 14 2014

Crossrefs

Cf. A002650.

Sequence in context: A178792 A007197 A247639 * A104091 A153292 A087457

Adjacent sequences: A002646 A002647 A002648 * A002650 A002651 A002652

Keyword

nonn

Author

N. J. A. Sloane

Extensions

a(26)-a(35) from Sean A. Irvine, May 08 2014

Status

approved