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Search: id:A089761
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A089761 Smallest k such that k*i^2 + 1 is prime for i = 1 to n. +0
1
1, 1, 4, 22, 58, 58, 58, 54972, 68112, 4748632 (list; graph; listen)
OFFSET

1,3

MAPLE

for n from 1 to 10 do for k from 1 do f:=0: for i from 1 to n do if not isprime(k*i^2+1) then f:=1: break fi od: if f=0 then printf("%d, ", k): break fi od od: (C. Ronaldo)

CROSSREFS

Sequence in context: A050773 A122241 A076525 this_sequence A098837 A104171 A036924

Adjacent sequences: A089758 A089759 A089760 this_sequence A089762 A089763 A089764

KEYWORD

hard,more,nonn

AUTHOR

Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Nov 22 2003

EXTENSIONS

Corrected and extended by C. Ronaldo (aga_new_ac(AT)hotmail.com), Dec 26 2004

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Last modified August 29 17:54 EDT 2008. Contains 143238 sequences.


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