A121236 - OEIS

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A121236

Primes of the form A001228(n) + 1 and A001228(n) - 1 where A001228 = orders of sporadic simple groups.

7919, 604801, 10200959, 44351999, 44352001, 50232961, 244823041, 460815505919, 64561751654399, 4089470473293004801, 4157776806543360001, 86775571046077562879 (list; graph; refs; listen; history; text; internal format)

	OFFSET	`1,1`
	COMMENTS	`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.`
	LINKS	`Table of n, a(n) for n=1..12.`
	FORMULA	`({A001228(n) + 1} UNION {A001228(n) - 1}) INTERSECTION A000040.`
	EXAMPLE	`a(1) = 7919 = A001228(1) - 1.` `a(2) = 604801 = A001228(5) + 1.` `a(3) = 10200959 = A001228(6) - 1.` `a(4) = 44351999 = A001228(7) - 1.` `a(5) = 44352001 = A001228(7) + 1.` `a(6) = 50232961 = A001228(8) + 1.` `a(7) = 244823041 = A001228(9) + 1.` `a(8) = 460815505919 = A001228(14) + 1.` `a(9) = 64561751654399 = A001228(17) - 1.` `a(10) = 4089470473293004801 = A001228(21) + 1.` `a(11) = 4157776806543360001 = A001228(22) + 1.` `a(12) = 86775571046077562879 = A001228(23) - 1.`
	CROSSREFS	`Cf. A000040, A001228.` `Sequence in context: A171111 A155178 A031922 * A233976 A001228 A036325` `Adjacent sequences: A121233 A121234 A121235 * A121237 A121238 A121239`
	KEYWORD	`easy,fini,full,nonn`
	AUTHOR	`Jonathan Vos Post, Aug 21 2006`
	STATUS	`approved`

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Last modified January 18 05:18 EST 2021. Contains 340250 sequences. (Running on oeis4.)