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A076597 Sqrt((n)*(n-1)*(n-2)*(n-3)+1) is a prime for given n. +0
1
4, 5, 6, 7, 8, 10, 11, 12, 13, 15, 17, 18, 21, 22, 23, 26, 28, 30, 32, 33, 37, 40, 41, 43, 46, 47, 48, 50, 52, 55, 56, 57, 58, 61, 62, 66, 67, 68, 70, 72, 78, 85, 87, 88, 91, 95, 96, 98, 102, 103, 105, 116, 117, 122, 127, 128, 132, 133, 136, 140, 142, 143, 146, 147, 150 (list; graph; listen)
OFFSET

1,1

COMMENT

Almost half of the values for n < 100 are primes.

EXAMPLE

40 is in the sequence because squareroot(40*39*38*37)+1 is 1481 which is prime.

MATHEMATICA

Select[Range[150], PrimeQ[Sqrt[ #*(# - 1)*(# - 2)*(# - 3) + 1]] &] (*Chandler*)

CROSSREFS

Sequence in context: A084991 A099070 A065342 this_sequence A121541 A023373 A078778

Adjacent sequences: A076594 A076595 A076596 this_sequence A076598 A076599 A076600

KEYWORD

easy,nonn

AUTHOR

Ben Thurston (benthrston(AT)netscape.net), Oct 20 2002

EXTENSIONS

Extended by Ray Chandler (rayjchandler(AT)sbcglobal.net), Aug 24 2006

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Last modified August 19 23:53 EDT 2008. Contains 142930 sequences.


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