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A119556
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Primes in the sequence f(n+1) = f(n)+((-1)^(n+1))*n!, with f(0)=0.
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0
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5, 101, 4421, 1226280710981, 115578717622022981, 32656499591185747972776747396512425885838364422981, 136372385605079432248118270297843987319730859689490659519593045108637838364422981
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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REFERENCES
| G. Balzarotti and P. P. Lava, Le sequenze di numeri interi, Hoepli, 2008, p. 160.
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EXAMPLE
| f(0)=0, f(1) = 0+((-1)^2)*1! = 1, f(2) = 1+((-1)^3)*2! = -1, f(3) = -1+((-1)^4)*3! = 5, which is prime, so 5 is the first term of the sequence.
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MAPLE
| P:=proc(n) local i, j; j:=0; for i from 1 by 1 to n do j:=j+((-1)^(i+1))*i!; if isprime(j) then print(i); fi; od; end: P(100);
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CROSSREFS
| Sequence in context: A041187 A074790 A009757 * A009765 A113073 A057207
Adjacent sequences: A119553 A119554 A119555 * A119557 A119558 A119559
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KEYWORD
| nonn,easy,changed
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AUTHOR
| Paolo P. Lava & Giorgio Balzarotti (paoloplava(AT)gmail.com), May 30 2006
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EXTENSIONS
| Offset changed to 1 (this is a list) from Bruno Berselli, Feb 16 2012
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