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%I #7 Jan 10 2013 02:38:34
%S 7919,604801,10200959,44351999,44352001,50232961,244823041,
%T 460815505919,64561751654399,4089470473293004801,4157776806543360001,
%U 86775571046077562879
%N Primes of the form A001228(n) + 1 and A001228(n) - 1 where A001228 = orders of sporadic simple groups.
%C This is not an arbitrary thing to do, as in some cases the sporadic group has an order depending on a specific power, as with A001228(1) + 1 = 7921 = 89^2 and A001228(3) + 1 = 175561 = 419^2. The largest integer to check is 1 + the order of the monster group, which is the semiprime 808017424794512875886459904961710757005754368000000001 = 18250906752127213 * 44272727693397225537389001926419074277.
%F ({A001228(n) + 1} UNION {A001228(n) - 1}) INTERSECTION A000040.
%e a(1) = 7919 = A001228(1) - 1.
%e a(2) = 604801 = A001228(5) + 1.
%e a(3) = 10200959 = A001228(6) - 1.
%e a(4) = 44351999 = A001228(7) - 1.
%e a(5) = 44352001 = A001228(7) + 1.
%e a(6) = 50232961 = A001228(8) + 1.
%e a(7) = 244823041 = A001228(9) + 1.
%e a(8) = 460815505919 = A001228(14) + 1.
%e a(9) = 64561751654399 = A001228(17) - 1.
%e a(10) = 4089470473293004801 = A001228(21) + 1.
%e a(11) = 4157776806543360001 = A001228(22) + 1.
%e a(12) = 86775571046077562879 = A001228(23) - 1.
%Y Cf. A000040, A001228.
%K easy,fini,full,nonn
%O 1,1
%A _Jonathan Vos Post_, Aug 21 2006
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