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 A182420 #14 Apr 15 2025 14:41:02
%S A182420 0,1,6,15,44,205,1218,8547,68440,615897,6158910,67747911,812974980,
%T A182420 10568674805,147961447354,2219421710235,35510747363504,
%U A182420 603682705179313,10866288693227382,206459485171319935,4129189703426398300,86712983771954363901
%N A182420 a(0)=0, a(n) = (a(n-1) XOR n) * n.
%H A182420 Harvey P. Dale, <a href="/A182420/b182420.txt">Table of n, a(n) for n = 0..449</a>
%F A182420 a(0)=0, a(n) = (a(n-1) XOR n) * n, where XOR is the bitwise exclusive-OR operator.
%t A182420 nxt[{n_,a_}]:={n+1,(n+1)BitXor[a,n+1]}; NestList[nxt,{0,0},30][[;;,2]] (* _Harvey P. Dale_, Jul 16 2024 *)
%o A182420 (Python)
%o A182420 a=0
%o A182420 for i in range(1,55):
%o A182420 print(a, end=', ')
%o A182420 a ^= i
%o A182420 a *= i
%Y A182420 Cf. A182251, A182390.
%K A182420 nonn,base
%O A182420 0,3
%A A182420 _Alex Ratushnyak_, Apr 28 2012