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A108151 a(n) = n^2 + 3*n + 1 if prime or 0 if composite. 0
5, 11, 19, 29, 41, 0, 71, 89, 109, 131, 0, 181, 0, 239, 271, 0, 0, 379, 419, 461, 0, 0, 599, 0, 701, 0, 811, 0, 929, 991, 0, 0, 0, 1259, 0, 0, 1481, 1559, 0, 1721, 0, 0, 1979, 2069, 2161, 0, 2351, 0, 2549, 0 (list; graph; refs; listen; history; internal format)
OFFSET

1,1

EXAMPLE

1^2+3*1+1=5 prime so a(1)=5

2^2+3*2+1=11 prime so a(2)=11

6^2+3*6+1=55 =5*11 composite so a(6)=0

CROSSREFS

Sequence in context: A038872 A141158 A130828 * A088059 A028387 A165900

Adjacent sequences:  A108148 A108149 A108150 * A108152 A108153 A108154

KEYWORD

nonn

AUTHOR

Pierre CAMI (pierre-cami(AT)bbox.fr), Jun 06 2005

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Last modified February 16 06:18 EST 2012. Contains 205860 sequences.