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 A090298 #18 Nov 24 2016 11:35:32 %S A090298 1,9,2,11,8,3,19,12,7,4,21,18,13,6,5,29,22,17,14,10,31,28,23,16,15,39, %T A090298 32,27,24,20,41,38,33,26,25,49,42,37,34,30,51,48,43,36,35,59,52,47,44, %U A090298 40,61,58,53,46,45,69,62,57,54,50,71,68,63,56,55,79,72,67,64,60,81,78 %N A090298 Permutation of natural numbers generated by 5-row array shown below. %C A090298 1 9 11 19 21 29 31 39... (A090771) %C A090298 2 8 12 18 22 28 32 38... (A090772) %C A090298 3 7 13 17 23 27 33 37... (A063226) %C A090298 4 6 14 16 24 26 34 36... (A090773) %C A090298 5 10 15 20 25 30 35 40... (A008587, excluding initial term) %C A090298 ----------------------------------------------------------- %C A090298 For such arrays A_k, here A_5, see a W. Lang comment on A113807, the A_7 case. However, in order to obtain A_5 one should take the last row as the first one after adding a 0 in front (thus getting a permutation of the nonnegative integers). - _Wolfdieter Lang_, Feb 02 2012 %Y A090298 Cf. A088520, A090243, A092260, A113807. %K A090298 easy,nonn %O A090298 1,2 %A A090298 _Giovanni Teofilatto_, Jan 25 2004 %E A090298 More terms from _Ray Chandler_, Feb 01 2004