This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A060568 #7 Jan 13 2025 17:34:42 %S A060568 0,0,0,0,0,0,0,0,0,4,0,3,4,6,9,11,12,15,16,7,3,0,2,4,6,9,11,13,14,8,4, %T A060568 2,0,2,4,7,8,10,12,10,6,4,2,0,2,4,6,8,9,12,9,6,4,2,0,2,5,7,7,14,11,9, %U A060568 7,4,2,0,2,4,5,15,12,11,8,6,5,2,0,2,2,18,15,13,10,8,7,4,2,0,1,20,16,14 %N A060568 Number of primes between n and R(n) where R(n) (A004086) is the digit reversal of n. %H A060568 John Tyler Rascoe, <a href="/A060568/b060568.txt">Table of n, a(n) for n = 1..10000</a> %e A060568 a(10) = 4, as there are four primes between 10 and 1. %o A060568 (Python) %o A060568 from sympy import primerange %o A060568 def A060568(n): %o A060568 x = (n, int(str(n)[::-1],10)) %o A060568 return len([i for i in primerange(min(x)+1,max(x))]) # _John Tyler Rascoe_, Jan 13 2025 %Y A060568 Cf. A000720, A074813. %K A060568 nonn,base,easy %O A060568 1,10 %A A060568 _Amarnath Murthy_, Apr 27 2001 %E A060568 More terms from Larry Reeves (larryr(AT)acm.org), May 10 2001