login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A145688 Primitive prime factors of the sequence 2k^2 + 1 in the order that they are found. 0
3, 19, 11, 17, 73, 43, 163, 67, 113, 131, 41, 193, 59, 241, 89, 883, 353, 1153, 139, 1459, 523, 1801, 641, 683, 2179, 257, 2593, 83, 107, 179, 97, 3529, 137, 1291, 4051, 491, 419, 1601, 1667, 601, 1873, 307, 2017, 2243, 211, 379, 827, 233, 467, 2731, 313, 8713 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

a(n) mod 8 = 1 or 3.

LINKS

Table of n, a(n) for n=1..52.

Bernhard Helmes, Prime sieving on the polynomial f(n)=2n^2+1.

CROSSREFS

Cf. A144851.

Sequence in context: A179767 A244605 A213602 * A178985 A266704 A185446

Adjacent sequences:  A145685 A145686 A145687 * A145689 A145690 A145691

KEYWORD

nonn

AUTHOR

Bernhard Helmes (pi(AT)devalco.de), Oct 16 2008

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified August 3 20:55 EDT 2021. Contains 346441 sequences. (Running on oeis4.)