id:A057034 - OEIS Search Results

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Difference between n!! and the first prime before n!! - 1.

+0
2

3, 2, 5, 2, 5, 4, 7, 4, 7, 4, 23, 2, 19, 2, 97, 2, 19, 64, 17, 62, 19, 4, 17, 58, 23, 64, 157, 122, 47, 106, 47, 4, 29, 146, 31, 64, 29, 8, 71, 8, 43, 32, 31, 128, 67, 122, 41, 2, 37, 146, 137, 122, 191, 142, 59, 128, 71, 284, 109, 274, 101, 218, 97, 32, 83, 158, 53, 166 (list; graph; listen)

	OFFSET	`4,1`
	COMMENT	`Analogous to the lesser Fortunate numbers but unlike them, all entries are not prime. Must odd entries are powers of two and all even entries are primes.`
	MATHEMATICA	`PrevPrime[ n_Integer ] := (k=n-1; While[ !PrimeQ[ k ], k-- ]; Return[ k ]); f[ n_Integer ] := (p = n!! - 1; q = PrevPrime[ p ]; Return[ p - q + 1 ]); Table[ f[ n ], {n, 4, 75} ]`
	CROSSREFS	`Sequence in context: A074830 A127750 A112528 this_sequence A075410 A023513 A069735` `Adjacent sequences: A057031 A057032 A057033 this_sequence A057035 A057036 A057037`
	KEYWORD	`nonn`
	AUTHOR	`Robert G. Wilson v (rgwv(AT)rgwv.com), Sep 09 2000`

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Last modified September 5 01:44 EDT 2008. Contains 143476 sequences.

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