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A122567 Twin primes modulo 4. 0
3, 1, 3, 3, 1, 1, 3, 1, 3, 1, 3, 3, 1, 3, 1, 1, 3, 3, 1, 1, 3, 1, 3, 3, 1, 3, 1, 1, 3, 3, 1, 3, 1, 1, 3, 1, 3, 3, 1, 3, 1, 3, 1, 3, 1, 1, 3, 1, 3, 1, 3, 3, 1, 1, 3, 1, 3, 3, 1, 1, 3, 1, 3, 3, 1, 1, 3, 1, 3, 3, 1, 3, 1, 1, 3, 1, 3, 3, 1, 3, 1, 1, 3, 1, 3, 1, 3, 1, 3, 3, 1, 3, 1, 3, 1, 1, 3, 3, 1, 3, 1, 3, 1, 3, 1 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..105.

EXAMPLE

The twin primes are 3,5,7,11,13,17,19,... and mod 4 is 3,1,3,3,1,1,3...

MAPLE

a[1]:=3:i:=2:for k from 5 to 3000 do if isprime(k) and isprime(k+2) then a[i]:=k mod 4:a[i+1]:=k+2 mod 4: i:=i+2 fi od: seq(a[n], n=1..i-1);

CROSSREFS

Cf. A001097.

Sequence in context: A075676 A298262 A124814 * A122431 A279340 A089607

Adjacent sequences:  A122564 A122565 A122566 * A122568 A122569 A122570

KEYWORD

nonn

AUTHOR

Miklos Kristof, Sep 21 2006

STATUS

approved

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Last modified June 16 19:49 EDT 2021. Contains 345068 sequences. (Running on oeis4.)