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 A359947 #7 Jan 22 2023 03:01:30
%S A359947 3,3,7,7,3,3,13,3,5,13,3,5,3,3,31,31,3,3,7,7,3,3,13,3,5,13,3,5,3,3,61,
%T A359947 3,5,61,3,5,3,3,13,3,5,13,3,5,3,3,31,31,3,3,7,7,3,3,13,3,5,13,3,5,3,3,
%U A359947 127,127,3,3,7,7,3,3,13,3,5,13,3,5,3,3,31,31
%N A359947 a(n) = n XOR A359946(n) (where XOR denotes the bitwise XOR operator).
%C A359947 All terms are prime.
%H A359947 Rémy Sigrist, <a href="/A359947/b359947.txt">Table of n, a(n) for n = 1..10000</a>
%e A359947 a(42) = 42 XOR A359946(42) = 42 XOR 39 = 13.
%o A359947 (PARI) { s = 0; for (n = 1, 80, for (v = 1, oo, if (!bittest(s, v) && isprime(p = bitxor(n, v)), print1 (p", "); s += 2^v; break))) }
%Y A359947 Cf. A359946.
%K A359947 nonn,base
%O A359947 1,1
%A A359947 _Rémy Sigrist_, Jan 19 2023