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 A336324 #10 Aug 06 2020 13:17:42 %S A336324 1,2,22,4,221,6,44,16,21,66,640,9,64,41,166,42,1666,46,65,660,19,9100, %T A336324 7,76,96,642,5,641,11,6409,6421,1640,964,646,656,657,77,6601,193,8,74, %U A336324 20,48,990,17,78,23,54,3,765,31,441,9646,6566,225,55,777,661,111,669,100,776,966,1110,194,12,9666 %N A336324 The power sandwiches sequence, version 1 (see Comments lines for definition). %C A336324 Imagine we would have a pair of adjacent integers in the sequence like [1951, 2020]. The sandwich would then be made of the rightmost digit R of a(n), the leftmost digit L of a(n+1) and, in between, L^R. The pair [1951, 2020] would then produce the power sandwich 122. Please note that the pair [2020, 1951] would produce the power and genuine sandwich 011 (we keep the leading zero: these are sandwiches after all, not integers). %C A336324 Now we want the sequence to be the lexicographically earliest sequence of distinct positive terms such that the successive sandwiches emerging from the sequence rebuild it, digit after digit. %H A336324 Carole Dubois, <a href="/A336324/b336324.txt">Table of n, a(n) for n = 1..541</a> %e A336324 The first successive sandwiches are: 122, 242, 2164, 4162, 166, 640964, ... %e A336324 The first one (122) is visible between a(1) = 1 and a(2) = 2; we get the sandwich by inserting 2^1 = 2. %e A336324 The second sandwich (242) is visible between a(2) = 2 and a(3) = 22; we get this sandwich by inserting 2^2 = 4 between 2 and 2. %e A336324 The third sandwich (2164) is visible between a(3) = 22 and a(4) = 4; we get this sandwich by inserting 4^2 = 16 between 2 and 4; etc. %e A336324 The successive sandwiches rebuild, digit by digit, the starting sequence. %Y A336324 Cf. A336325 (same idea, but between L and R we insert R^L instead of L^R), A335600 (poor sandwiches), A335854 (digital-root sandwiches), A335886 (heavy sandwiches). %K A336324 base,nonn %O A336324 1,2 %A A336324 _Carole Dubois_ and _Eric Angelini_, Jul 17 2020