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 A237448 #17 Oct 28 2019 02:41:21 %S A237448 1,2,2,3,1,3,4,1,3,4,5,1,2,4,5,6,1,2,4,5,6,7,1,2,3,5,6,7,8,1,2,3,5,6, %T A237448 7,8,9,1,2,3,4,6,7,8,9,10,1,2,3,4,6,7,8,9,10,11,1,2,3,4,5,7,8,9,10,11, %U A237448 12,1,2,3,4,5,7,8,9,10,11,12,13,1,2,3,4,5,6,8,9,10,11,12,13 %N A237448 Square array T(row >= 1, col >= 1): The first row, row=1, T(1,col) = col = A000027. When row > col, T(row,col) = row, otherwise (when 1 < row <= col), T(row,col) = row-1. %C A237448 This is transpose of A237447, please see comments there. %H A237448 Antti Karttunen, <a href="/A237448/b237448.txt">Table of first 144 antidiagonals of array, flattened</a> %F A237448 As a one-dimensional sequence: %F A237448 If A010054(n-1) = 1 [that is, if n is in A000124], then a(n) = A002024(n), otherwise, if A004736(n) < A002260(n), a(n) = A002260(n), and if A004736(n) >= A002260(n), a(n) = A002260(n)-1. %F A237448 Equivalently, as a square array T: %F A237448 When col < row, T(row,col) = row, for 1 < row <= col, T(row,col) = row-1, and for the first row T(1,col) = col = A000027(col). %F A237448 Can be computed also as a transposed version of the infinite limit of the finite square arrays in sequence A237265: T(row,col) = A237265((A000330(max(row,col)-1)+1) + (max(row,col)*(col-1)) + (row-1)). %e A237448 The top left 9 X 9 corner of this infinite square array: %e A237448 1 2 3 4 5 6 7 8 9 %e A237448 2 1 1 1 1 1 1 1 1 %e A237448 3 3 2 2 2 2 2 2 2 %e A237448 4 4 4 3 3 3 3 3 3 %e A237448 5 5 5 5 4 4 4 4 4 %e A237448 6 6 6 6 6 5 5 5 5 %e A237448 7 7 7 7 7 7 6 6 6 %e A237448 8 8 8 8 8 8 8 7 7 %e A237448 9 9 9 9 9 9 9 9 8 %o A237448 (Scheme) %o A237448 (define (A237448 n) (cond ((= 1 (A010054 (- n 1))) (A002024 n)) ((< (A004736 n) (A002260 n)) (A002260 n)) (else (- (A002260 n) 1)))) %Y A237448 Transpose: A237447. %Y A237448 The leftmost column and the topmost row: A000027. Second row: A054977. Central diagonal: A028310 (note the different starting offsets). %Y A237448 Antidiagonal sums: A074148. %Y A237448 Cf. A237265, A000330, A002024, A002260, A004736, A000124, A010054. %K A237448 nonn,tabl,easy %O A237448 1,2 %A A237448 _Antti Karttunen_, Feb 10 2014