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 A069256 #12 Nov 03 2023 06:58:48
%S A069256 1,2,16,32,32,32,32,512,16,64,16,512,32,64,512,8192,512,32,16,1024,
%T A069256 512,32,32,8192,32,64,16,1024,32,1024,128,131072,256,1024,1024,512,32,
%U A069256 32,512,16384,128,1024,16,512,512,64,64,131072,32,64,8192,1024,32,32,512
%N A069256 Size of the Sylow 2-subgroup of the group GL_2(Z_n): maximal power of 2 that divides A000252(n).
%H A069256 Amiram Eldar, <a href="/A069256/b069256.txt">Table of n, a(n) for n = 1..10000</a>
%F A069256 Multiplicative with a(2^e) = 2^(4*e-3) and a(p^e) = power of 2 in prime factorization of (p - 1)*(p^2-1) for an odd prime p. - _Vladeta Jovovic_, Apr 17 2002
%t A069256 f[p_, e_] := 2^IntegerExponent[(p-1)*(p^2-1), 2]; f[2, e_] := 2^(4*e-3); a[1] = 1; a[n_] := Times @@ f @@@ FactorInteger[n]; Array[a, 100] (* _Amiram Eldar_, Nov 02 2023 *)
%o A069256 (PARI) a(n) = {my(f = factor(n)); prod(i = 1, #f~, if(f[i, 1] == 2, 1 << (4*f[i, 2]-3), 1 << valuation((f[i, 1]-1)*(f[i, 1]^2-1), 2)));} \\ _Amiram Eldar_, Nov 03 2023
%Y A069256 Cf. A000252, A069177.
%K A069256 nonn,easy,mult
%O A069256 1,2
%A A069256 Sharon Sela (sharonsela(AT)hotmail.com), Apr 14 2002
%E A069256 More terms from _Vladeta Jovovic_, Apr 17 2002