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A121944 Composite number of the form 4n^2+1. 1
65, 145, 325, 485, 785, 901, 1025, 1157, 1445, 1765, 1937, 2117, 2305, 2501, 2705, 3365, 3601, 3845, 4097, 4625, 4901, 5185, 5777, 6085, 6401, 6725, 7397, 7745, 8465, 9217, 9605, 10001, 10405, 10817, 11237, 11665, 12545, 12997, 13925, 14885, 16385 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..41.

MATHEMATICA

Select[Table[4n^2 + 1, {n, 70}], ! PrimeQ[ # ] &]

CROSSREFS

a(n) are elements of A053755 = 4*n^2 + 1, beside 1 that are not prime, that is they do not lie in A002496 = Primes of form n^2 + 1.

Sequence in context: A092226 A211255 A226926 * A044316 A044697 A044397

Adjacent sequences:  A121941 A121942 A121943 * A121945 A121946 A121947

KEYWORD

nonn

AUTHOR

Tanya Khovanova, Sep 03 2006

STATUS

approved

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Last modified January 23 21:40 EST 2017. Contains 281216 sequences.