A084290 - OEIS

A084290

Difference between consecutive primes arising before difference (d=2) between twin primes. In A001223, terms before the ones that equal 2.

1, 2, 4, 4, 6, 4, 6, 4, 4, 4, 6, 10, 6, 10, 4, 4, 6, 6, 4, 4, 10, 10, 10, 4, 12, 6, 6, 4, 10, 6, 12, 10, 4, 4, 4, 6, 10, 10, 10, 4, 22, 6, 18, 6, 4, 12, 4, 4, 10, 4, 6, 6, 4, 4, 12, 4, 4, 4, 18, 16, 4, 10, 12, 4, 12, 16, 4, 16, 16, 12, 6, 4, 6, 12, 10, 4, 4, 10, 12, 4, 6, 28, 10, 4, 22, 4, 28, 6

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OFFSET

1,2

LINKS

T. D. Noe, Table of n, a(n) for n = 1..10000

MATHEMATICA

t = {}; s = 1; Do[s1 = Prime[n] - Prime[n - 1]; If[Equal[s1, 2], AppendTo[t, s]]; s = s1, {n, 2, 1000}]; t

PROG

(PARI) list(lim) = {my(prv = 3, dprv = 1, d); forprime(p = 5, lim, d = p - prv; if(d == 2, print1(dprv, ", ")); prv = p; dprv = d); } \\ Amiram Eldar, Feb 08 2025

CROSSREFS

Cf. A001223, A084291.

Sequence in context: A049782 A372785 A091666 * A372787 A372791 A062011

Adjacent sequences: A084287 A084288 A084289 * A084291 A084292 A084293

KEYWORD

nonn

AUTHOR

Labos Elemer, May 26 2003

STATUS

approved