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 A173028 #16 Dec 29 2012 13:17:16 %S A173028 1,3,2,4,9,6,5,13,29,7,16,45,43,35,8,19,56,57,52,15,10,22,67,186,181, %T A173028 58,51,11,25,78,223,226,77,199,55,12,28,89,260,271,96,265,82,61,14,31, %U A173028 262,297,316,115,331,109,91,71,17,34,291,334,361,351,397,136,317,106,87,18 %N A173028 Partition of the row numbers of the Wythoff array W: two numbers are in the same row if and only if their rows in W have (essentially) a common divisor greater than 1. %C A173028 (Row 1) = A173027, (Row 2) = A220249. Every positive integer occurs exactly once, so that, as a sequence, this is a permutation of the natural numbers. %F A173028 Let R(n,k) be the number in row n, column k. After Row 1 (A173027), %F A173028 inductively, R(n,1) is the least positive integer not in the first n-1 %F A173028 rows, and the rest of row n consists of the numbers of rows X of the %F A173028 Wythoff array W for X a multiple of a tail of row R(n,1) of W. %e A173028 First four rows of R: %e A173028 1...3....4....5.....16....19....22...25...28... %e A173028 2...9....13...45....56....67....78...89...262.. %e A173028 6...29...43...57....186...223...260..297..334... %e A173028 7...35...52...181...226...271...316..361..1063... %e A173028 For example, row 3 begins with 6, which is the least positive %e A173028 integer not in rows 1 and 2. Row 6 of W is (14,23,37,60,...) %e A173028 Row 29 of W is (74,120,194,...) = 2*(37,60,97...). %e A173028 Row 43 of W is (111,180,291,...) = 3*(37,60,97,...). %e A173028 So row 3 of R begins with (6,29,43...) as there are no other rows %e A173028 of W numbered <43 which are multiples of row 6 of W. %Y A173028 Cf. A000045, A035513, A173027, A220249. %K A173028 nonn,tabl %O A173028 1,2 %A A173028 _Clark Kimberling_, Feb 07 2010 %E A173028 Corrections (these have been made): a(31) should read 223 instead of 225, a(63) 317 instead of 314 - _K. G. Stier_, Dec 21 2012