Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%I #3 Mar 30 2012 18:40:49
%S 727,5623,21611,131771,751691,8311687,16867447,25431851,71014331,
%T 109056251,350550731,3170478247,4435959611,4678970407,6353205851,
%U 9659548091,11977770247,26525659687,29365277771,39262233611,52986054967
%N Primes of the form 9*(p^4)-2 or 9*(p^4)+2, arising in Paley-Hadamard difference sets.
%C Polhill is able to construct Paley-Hadamard difference sets of the Stanton-Sprott family in groups of the form (Z_3)^2 X (Z_p)^4t X (Z_(9p^4t)+2 or -2 when 9*(p^4t)-2 or 9*(p^4t)+2 is a prime power. In this sequence, we are taking just the t=1 case, a prime power as first power of prime.
%D John Bowen Polhill, Paley partial difference sets in groups with order not a prime power, 1046th Meeting of the AMS, Washington, DC, January 5-8, 2009.
%e a(1) = 9*(3^4) - 2 = 727 is prime. a(2) = 9*(5^4) - 2 = 5623 is prime. a(3) = 9*(7^4) + 2 = 21611. a(4) = 9*(11^4) + 2 = 131771. a(5) = 9*(17^4) + 2 = 751691. a(6) = 9*(31^4) - 2 = 8311687. a(7) = 9*(37^4) - 2 = 16867447. a(8) = 9*(41^4) + 2 = 25431851.
%K easy,nonn
%O 1,1
%A _Jonathan Vos Post_, Mar 01 2009
%E More terms from _R. J. Mathar_, Mar 06 2009