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 A226532 #22 Jan 01 2025 22:12:01 %S A226532 1,2,6,4,30,3,210,8,36,15,2310,24,30030,105,5,16,510510,72,9699690, %T A226532 120,35,1155,223092870,12,900,15015,216,840,6469693230,10, %U A226532 200560490130,32,385,255255,7,9,7420738134810,4849845,5005,60,304250263527210,70,13082761331670030,9240,1080,111546435,614889782588491410 %N A226532 If n = Product_{i>0} prime(i)^e(i), then a(n) = Product_{i>0} prime(i)^(XOR_{j>=i} e(j)), where XOR is bitwise XOR. %C A226532 This sequence is a permutation of the natural numbers. %C A226532 The powers of 2 are the fixed points of this sequence. %C A226532 a(prime(i)) = A002110(i) for any i > 0. %C A226532 a(i^2) = a(i)^2 for any i > 0. %C A226532 a(A019565(n)) = A019565(A006068(n)) for any n >= 0. %H A226532 Paul Tek, <a href="/A226532/b226532.txt">Table of n, a(n) for n = 1..2370</a> %H A226532 Paul Tek, <a href="/A226532/a226532.txt">PERL program for this sequence</a> %H A226532 <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a> %e A226532 a(50) = a(2^1 * 3^0 * 5^2) %e A226532 = 2^xor(1,0,2) * 3^xor(0,2) * 5^xor(2) %e A226532 = 2^3 * 3^2 * 5^2 %e A226532 = 1800. %o A226532 (Perl) # See Tek link. %o A226532 (Haskell) %o A226532 import Data.Bits (xor) %o A226532 a226532 n = product $ zipWith (^) %o A226532 a000040_list (scanr1 xor $ a067255_row n :: [Integer]) %o A226532 -- _Reinhard Zumkeller_, Jun 11 2013 %Y A226532 Cf. A006068. %Y A226532 Cf. A226569 (inverse), A067255, A000040. %K A226532 nonn %O A226532 1,2 %A A226532 _Paul Tek_, Jun 10 2013