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 A265903 #39 Sep 20 2016 13:24:50 %S A265903 1,3,2,5,7,4,6,12,15,8,9,14,27,31,16,10,21,30,58,63,32,11,24,48,62, %T A265903 121,127,64,13,26,54,106,126,248,255,128,17,29,57,116,227,254,503,511, %U A265903 256,18,38,61,120,242,475,510,1014,1023,512,19,42,86,125,247,496,978,1022,2037,2047,1024,20,45,96,192,253,502,1006,1992,2046,4084,4095,2048 %N A265903 Square array read by descending antidiagonals: A(1,k) = A188163(k), and for n > 1, A(n,k) = A087686(1+A(n-1,k)). %C A265903 Square array A(n,k) [where n is row and k is column] is read by descending antidiagonals: A(1,1), A(1,2), A(2,1), A(1,3), A(2,2), A(3,1), etc. %C A265903 For n >= 3, each row n lists the numbers that appear n times in A004001. See also A051135. %H A265903 Antti Karttunen, <a href="/A265903/b265903.txt">Table of n, a(n) for n = 1..210; the first 20 antidiagonals of array</a> %H A265903 <a href="/index/Ho#Hofstadter">Index entries for Hofstadter-type sequences</a> %H A265903 <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a> %F A265903 For the first row n=1, A(1,k) = A188163(k), for rows n > 1, A(n,k) = A087686(1+A(n-1,k)). %e A265903 The top left corner of the array: %e A265903 1, 3, 5, 6, 9, 10, 11, 13, 17, 18, 19 %e A265903 2, 7, 12, 14, 21, 24, 26, 29, 38, 42, 45 %e A265903 4, 15, 27, 30, 48, 54, 57, 61, 86, 96, 102 %e A265903 8, 31, 58, 62, 106, 116, 120, 125, 192, 212, 222 %e A265903 16, 63, 121, 126, 227, 242, 247, 253, 419, 454, 469 %e A265903 32, 127, 248, 254, 475, 496, 502, 509, 894, 950, 971 %e A265903 64, 255, 503, 510, 978, 1006, 1013, 1021, 1872, 1956, 1984 %e A265903 128, 511, 1014, 1022, 1992, 2028, 2036, 2045, 3864, 3984, 4020 %e A265903 256, 1023, 2037, 2046, 4029, 4074, 4083, 4093, 7893, 8058, 8103 %e A265903 512, 2047, 4084, 4094, 8113, 8168, 8178, 8189, 16006, 16226, 16281 %e A265903 1024, 4095, 8179, 8190, 16292, 16358, 16369, 16381, 32298, 32584, 32650 %e A265903 ... %o A265903 (Scheme) %o A265903 (define (A265903 n) (A265903bi (A002260 n) (A004736 n))) %o A265903 (define (A265903bi row col) (if (= 1 row) (A188163 col) (A087686 (+ 1 (A265903bi (- row 1) col))))) %Y A265903 Inverse permutation: A267104. %Y A265903 Transpose: A265901. %Y A265903 Row 1: A188163. %Y A265903 Row 2: A266109. %Y A265903 Row 3: A267103. %Y A265903 For the known and suspected columns, see the rows listed for transposed array A265901. %Y A265903 Cf. A004001, A051135, A087686. %Y A265903 Cf. A265900 (main diagonal), A265909 (submain diagonal). %Y A265903 Cf. A162598 (column index of n in array), A265332 (row index of n in array). %Y A265903 Cf. also permutations A267111, A267112. %K A265903 nonn,tabl %O A265903 1,2 %A A265903 _Antti Karttunen_, Dec 18 2015