A330468 - OEIS

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A330468

Numbers k where the difference (least prime > 10^k) - (greatest prime < 10^k) sets a record.

1, 3, 4, 9, 16, 21, 24, 28, 34, 66, 82, 92, 117, 122, 135, 218, 232, 314, 387, 443, 478, 617, 652, 787, 1031, 1157, 1440, 1625, 1872, 1920, 2038, 2424, 2692, 3235, 3331, 3798, 4944, 5202, 5241, 5938, 7572, 7847

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,2

LINKS

Table of n, a(n) for n=1..42.

EXAMPLE

a(1) = 1: 11 - 7 = 4;

a(2) = 3: 1009 - 997 = 12, whereas 101 - 97 = 4 <= a(1).

PROG

(PARI) d=0; for(k=1, 500, my(t=10^k, dd=nextprime(t)-precprime(t)); if(dd>d, print1(k, ", "); d=dd))

CROSSREFS

Cf. A003617, A003618, A038804, A331834.