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 A152922 #9 Oct 17 2024 08:27:01 %S A152922 2,8,128,2048,8388608,2147483648,34359738368,576460752303423488, %T A152922 664613997892457936451903530140172288, %U A152922 47890485652059026823698344598447161988085597568237568 %N A152922 a(n) = 2^(2*p-1)/4, where p is A000043(n). %C A152922 Ultraperfect numbers (A139306), divided by 4. %H A152922 Amiram Eldar, <a href="/A152922/b152922.txt">Table of n, a(n) for n = 1..15</a> %F A152922 a(n) = A139306(n)/4 = A152921(n)/2. %t A152922 2^(2 * MersennePrimeExponent[Range[10]] - 3) (* _Amiram Eldar_, Oct 17 2024 *) %Y A152922 Cf. A000043, A139290, A139306, A152921, A152923. %K A152922 nonn %O A152922 1,1 %A A152922 _Omar E. Pol_, Dec 15 2008 %E A152922 a(9)-a(10) from _Amiram Eldar_, Oct 17 2024