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A082075 First differences of primes of the form 4*k+3 (A002145). 5
4, 4, 8, 4, 8, 12, 4, 12, 8, 4, 8, 4, 20, 4, 20, 4, 8, 12, 12, 4, 12, 12, 8, 12, 12, 4, 12, 12, 12, 8, 12, 24, 4, 20, 16, 12, 8, 12, 4, 36, 12, 8, 4, 20, 4, 12, 8, 4, 8, 4, 20, 24, 16, 8, 16, 12, 8, 12, 12, 12, 4, 12, 24, 8, 28, 8, 12, 4, 8, 36, 24, 12, 4, 12, 20, 4, 20, 4, 20, 4, 8, 28, 20, 4 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Amiram Eldar, Table of n, a(n) for n = 1..10000

FORMULA

a(n) = A002145(n+1) - A002145(n).

EXAMPLE

The first and second primes of the form 4*k+3 are 3 and 7, so a(1) = 7-3 = 4.

MATHEMATICA

k=0; m=4; r=3; Do[s=Mod[Prime[n], m]; If[Equal[s, r], rp=ep; k=k+1; ep=Prime[n]; Print[ep-rp]; ], {n, 1, 1000}]

CROSSREFS

Cf. A002144, A002145, A082073, A082074, A082075, A082076.

Sequence in context: A273428 A273765 A273854 * A243641 A276620 A276681

Adjacent sequences:  A082072 A082073 A082074 * A082076 A082077 A082078

KEYWORD

nonn

AUTHOR

Labos Elemer, Apr 07 2003

STATUS

approved

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Last modified June 24 06:17 EDT 2021. Contains 345416 sequences. (Running on oeis4.)