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 A220099 #9 Aug 13 2018 09:12:19 %S A220099 44,66,63,94,91,81,80,101,100,158,154,133,131,153,151,222,218,185,183, %T A220099 190,186,206,202,237,235,318,314,269,267,270,266,286,282,321,319,414, %U A220099 410,353,351,350,346,366,362,382,378,398,394,437,435,542,538,469,467,462,458 %N A220099 Sum of the eight nearest neighbors of n in a double spiral with positive integers and 1 at the center. %C A220099 Double spiral begins: %C A220099 . %C A220099 82---84---86---88---90---92---94---96---98 %C A220099 | %C A220099 80 51---53---55---57---59---61---63---65 %C A220099 | | | %C A220099 78 49 26---28---30---32---34---36 67 %C A220099 | | | | | %C A220099 76 47 24 11---13---15---17 38 69 %C A220099 | | | | | | | %C A220099 74 45 22 9 2----4 19 40 71 %C A220099 | | | | | | | | | %C A220099 72 43 20 7 1 6 21 42 73 %C A220099 | | | | | | | | | %C A220099 70 41 18 5----3 8 23 44 75 %C A220099 | | | | | | | %C A220099 68 39 16---14---12---10 25 46 77 %C A220099 | | | | | %C A220099 66 37---35---33---31---29---27 48 79 %C A220099 | | | %C A220099 64---62---60---58---56---54---52---50 81 %C A220099 | %C A220099 99---97---95---93---91---89---87---85---83 %Y A220099 Cf. A220098, A220100. %K A220099 nonn,easy %O A220099 1,1 %A A220099 _Alex Ratushnyak_, Dec 04 2012