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 A379272 #14 Feb 24 2025 09:27:13
%S A379272 1,2,3,4,6,8,10,14,18,22,33,40,54,74,93,116,172,204,268,378,482,584,
%T A379272 905,1036,1378,1858,2520,3002,4700,5298,7089,9456,12420,15452,24160,
%U A379272 26542,36646,47634,64183,75568,126118,135226,188098,244172,329098,383142,626452,689466,980284,1229296,1691506
%N A379272 Number of binary min-heaps on n elements from the set {0,1} that give a max-heap when reversed.
%C A379272 If n is odd then a(n) is even.
%H A379272 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/Heap.html">Heap</a>
%H A379272 Wikipedia, <a href="https://en.wikipedia.org/wiki/Binary_heap">Binary heap</a>
%e A379272 a(5) = 8: 00000, 00001, 00011, 00101, 00111, 01011, 01111, 11111.
%e A379272 a(6) = 10: 000000, 000001, 000011, 000101, 000111, 001011, 001111, 010111, 011111, 111111. Min-heaps on 6 elements from the set {0,1} that do not give a max-heap when reversed are: 000010, 000100, 000110, 001001, 001101, 010110.
%e A379272 a(7) = 14: 0000000, 0000001, 0000011, 0000101, 0000111, 0001011, 0001111, 0010011, 0010111, 0011011, 0011111, 0101111, 0111111, 1111111.
%Y A379272 Cf. A056971, A091980, A273755.
%K A379272 nonn
%O A379272 0,2
%A A379272 _Alois P. Heinz_, Feb 18 2025