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 A034596 #10 Aug 13 2024 22:54:07 %S A034596 5,11,12,13,15,16,19,29,30,42,43,45,46,75,88,89,97,103,113,117,125, %T A034596 126,137,149,150,162,163,174,198,200,225,237,252,258,267,268,273,276, %U A034596 280,286,323,329,330,339,346,351,359,366,374,382,387,392,393,400,407,412 %N A034596 a(n) preceded and followed by nextprime(a(n)) is a prime. %H A034596 Andrew Howroyd, <a href="/A034596/b034596.txt">Table of n, a(n) for n = 1..10000</a> %e A034596 a(n)=323 -> nextprime(a(n)) is 331 so '331323331' is prime. %o A034596 (PARI) isok(n)=my(x=digits(nextprime(n+1))); isprime(fromdigits(concat([x, digits(n), x]))) \\ _Andrew Howroyd_, Aug 13 2024 %Y A034596 See also A034591-A034595. %K A034596 nonn,base %O A034596 1,1 %A A034596 _Patrick De Geest_, Oct 15 1998 %E A034596 Offset changed by _Andrew Howroyd_, Aug 13 2024