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A145689 Primitive prime factors of the sequence 4k^2 + 1 in the order that they are found. 0
5, 17, 37, 13, 101, 29, 197, 257, 401, 97, 577, 677, 157, 53, 41, 89, 1297, 1601, 353, 149, 73, 461, 61, 541, 2917, 3137, 673, 277, 769, 241, 4357, 5477, 109, 1217, 173, 269, 7057, 569, 1549, 8101, 1693, 8837, 709, 113, 137, 2081, 373, 661, 2333, 12101, 193 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

a(n) mod 8 = 1 or 5, all primes p mod 8 = 1 or 5 can be found on this sequence.

LINKS

Table of n, a(n) for n=1..51.

Bernhard Helmes, Prime sieving on the polynomial f(n)=4n^2+1.

CROSSREFS

Sequence in context: A123669 A121325 A256970 * A321658 A080167 A060245

Adjacent sequences:  A145686 A145687 A145688 * A145690 A145691 A145692

KEYWORD

nonn

AUTHOR

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

STATUS

approved

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Last modified September 19 18:36 EDT 2021. Contains 347564 sequences. (Running on oeis4.)