A038804 Difference between largest n-digit prime and smallest (n+1)-digit prime.

4, 4, 12, 34, 12, 20, 28, 18, 70, 52, 26, 50, 66, 58, 48, 124, 6, 14, 90, 50, 218, 36, 140, 264, 136, 208, 202, 540, 346, 68, 60, 70, 70, 604, 92, 226, 124, 192, 60, 138, 228, 146, 138, 84, 18, 154, 74, 226, 66, 208, 444, 558, 348, 322, 132, 596, 372, 308, 160, 168

Offset: 1

Author

Jeff Burch

Keywords

• nonn
• base

Comments

Records: 4, 12, 34, 70, 124, 218, 264, 540, 604, 670, 754, 1182, ..., . - Robert G. Wilson v, Jan 23 2020

Examples

			7 = greatest prime with 1 digit, 11 next smallest prime with 2 digits so a(1)=4.
97 = greatest prime with 2 digits, 101 next smallest prime with 3 digits so a(2)=4.
		

Links

• Giovanni Resta, Table of n, a(n) for n = 1..8000 (terms 1..1000 from Pierre CAMI, terms 1001..4000 from Robert G. Wilson v)
• Pierre CAMI, PFGW script
• Vasiliy Danilov, Smallest & largest n-digit primes.
• Eric Weisstein's World of Mathematics, Next Prime.
• Eric Weisstein's World of Mathematics, Previous Prime.

Crossrefs

Cf. A033873, A033874, A003617, A003618, A058249.

Programs

Mathematica

(NextPrime[#]-NextPrime[#,-1])&/@(10^Range[100])  (* Harvey P. Dale, Mar 23 2011 *)

Formula

a(n) = A033873(n) + A033874(n). - Zak Seidov, Sep 13 2016

Extensions

Corrected and edited by Patrick De Geest, Nov 06 2004