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 A020336 #20 Apr 06 2021 04:53:10 %S A020336 9,18,27,36,45,54,63,520,585,650,715,780,845,910,975,1040,1105,1170, %T A020336 1235,1300,1365,1430,1495,1560,1625,1690,1755,1820,1885,1950,2015, %U A020336 2080,2145,2210,2275,2340,2405,2470,2535,2600,2665,2730,2795,2860,2925,2990,3055 %N A020336 Numbers whose base-8 representation is the juxtaposition of two identical strings. %H A020336 Amiram Eldar, <a href="/A020336/b020336.txt">Table of n, a(n) for n = 1..10000</a> %F A020336 a(n) = n*8^floor(log_8(n)+1) + n. - _Ilya Gutkovskiy_, Jan 26 2018 %e A020336 650_10 = 1212_8. - _Jon E. Schoenfield_, Feb 12 2021 %t A020336 a[n_] := n + n*8^Floor[Log[8, n] + 1]; Array[a, 50] (* _Amiram Eldar_, Apr 06 2021 *) %Y A020336 Cf. A020330, A020331, A020332, A020333, A020334, A020335, A020337, A020338. %K A020336 nonn,base %O A020336 1,1 %A A020336 _David W. Wilson_, Melia Aldridge (ma38(AT)spruce.evansville.edu)