A053695 Differences between record prime gaps.

1, 2, 2, 2, 6, 4, 2, 2, 12, 2, 8, 8, 20, 14, 10, 16, 2, 4, 14, 16, 6, 26, 30, 10, 2, 12, 14, 2, 32, 6, 4, 28, 16, 18, 28, 2, 10, 62, 8, 4, 6, 12, 4, 10, 14, 2, 16, 2, 6, 42, 6, 14, 50, 22, 42, 50, 12, 26, 2, 100, 10, 8, 208, 52, 14, 22, 4, 24, 24, 56, 28, 14, 72, 34, 12, 22

Offset

1,2

Comments

The largest known term of this sequence is a(63) = 1132 - 924 = 208. This seems rather strange for a(63) > 2*100+7 where 100 = max {a(k)| k < 63}. {1,2,4,6,8,10,12,14,16,18,20,22,24,26,28,30,32,34,42,50,52,56,62,72,100,208} is the set of the distinct first 75 terms of the sequence. What is the smallest number m such that a(m) = 36? - Farideh Firoozbakht, May 30 2014

Conjecture: a(n) <= A005250(n). Based on the equivalent statement at A005250: A005250(n+1) / A005250(n) <= 2. - John W. Nicholson, Dec 30 2015

Links

John W. Nicholson, Table of n, a(n) for n = 1..81

Alexei Kourbatov, On the nth record gap between primes in an arithmetic progression. International Mathematical Forum, Vol. 13, 2018, No. 2, 65-78, arXiv:1709.05508v3 [math.NT].

Eric Weisstein's World of Mathematics, Prime Gaps

Wikipedia, Prime gap

Formula

a(n) = A005250(n+1) - A005250(n).

A005250(n+1) = 1 + Sum_{i=1..n} a(i). - John W. Nicholson, Dec 29 2015

Mathematica

m = 2; r = 0; Differences@ Reap[Monitor[Do[If[Set[d, Set[n, NextPrime[m]] - m] > r, Set[r, d]; Sow[d]]; m = n, {i, 10^7}], i]][[-1, -1]] (* Michael De Vlieger, Oct 30 2021 *)

Crossrefs

Cf. A000101, A001223, A002386, A005250, A053686.

Sequence in context: A126615 A158524 A054274 * A210550 A208659 A209752

Adjacent sequences: A053692 A053693 A053694 * A053696 A053697 A053698

Keyword

nonn,nice,hard

Author

Jeff Burch, Mar 23 2000

Extensions

Missing term 1 and more terms added by Farideh Firoozbakht, May 30 2014

a(75)-a(76) from John W. Nicholson, Feb 27 2018

Status

approved