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 A077352 #36 May 19 2025 09:43:08 %S A077352 1,6,31,156,7801,390051,19502551,9751275501,4875637750501, %T A077352 2437818875250501,12189094376252505001,60945471881262525005001, %U A077352 304727359406312625025005001,1523636797031563125125025005001,76181839851578156256251250250050001,3809091992578907812812562512502500050001 %N A077352 a(n) = (concatenation in ascending order of divisors of 2^n)/2^n. %H A077352 Paolo Xausa, <a href="/A077352/b077352.txt">Table of n, a(n) for n = 0..80</a> %F A077352 For n>=1, a(n) = (a(n-1)*2^(n-1)*10^(floor(log_10(2^n))+1)+2^n)/2^n. - _Sam Alexander_, Feb 27 2005 %e A077352 a(6) = 1248163264/64 = 19502551. %p A077352 a:= n-> parse(cat(2^i$i=0..n))/2^n: %p A077352 seq(a(n), n=0..15); # _Alois P. Heinz_, May 16 2025 %t A077352 A077352[n_] := FromDigits[Flatten[IntegerDigits[Divisors[#]]]]/# & [2^n]; %t A077352 Array[A077352, 16, 0] (* or *) %t A077352 FoldList[10^IntegerLength[2^#2]*#/2 + 1 &, 1, Range[15]] (* _Paolo Xausa_, May 19 2025 *) %Y A077352 Cf. A000079, A034887, A059268, A077351, A069872, A077353. %K A077352 base,nonn %O A077352 0,2 %A A077352 _Amarnath Murthy_, Nov 05 2002 %E A077352 Offset corrected by _Sean A. Irvine_, May 16 2025