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 A239659 #13 Dec 31 2020 11:11:15 %S A239659 1,4,6,8,15,18,21,33,37,41,56,61,64,69,78,87,93,99,127,134,141,153, %T A239659 165,173,181,189,220,229,238,277,287,297,339,350,355,360,371,389,407, %U A239659 419,431,491,504,509,522,543,564,578,584,590,604,660,675,690,762,778,794,857,874,881,888,905,932,959,977,989,1007,1098 %N A239659 Sum of first n parts of the spiral described in A239660. %C A239659 We can find the spiral on the terraces of the stepped pyramid described in A244050. - Omar E. Pol, Dec 07 2016 %e A239659 If written as an irregular triangle in which row lengths is A237271 the sequence begins: %e A239659 1; %e A239659 4; %e A239659 6, 8; %e A239659 15; %e A239659 18, 21; %e A239659 33; %e A239659 37, 41; %e A239659 56; %e A239659 61, 64, 69; %e A239659 78, 87; %e A239659 93, 99; %e A239659 127; %e A239659 134, 141; %e A239659 153, 165; %e A239659 173, 181, 189; %e A239659 220; %e A239659 229, 238; %e A239659 277; %e A239659 287, 297; %e A239659 339; %e A239659 350, 355, 360, 371; %e A239659 389, 407; %e A239659 419, 431; %e A239659 491; %e A239659 504, 509, 522; %e A239659 ... %e A239659 Right border gives A024916. %Y A239659 Partial sums of A237270. %Y A239659 Cf. A000203, A024916, A196020, A237593, A237271, A239660, A244050, A245092, A262626. %K A239659 nonn,tabf %O A239659 1,2 %A A239659 _Omar E. Pol_, Mar 31 2014