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%I #11 Sep 20 2016 13:27:15
%S 1,1,3,1,3,7,1,3,8,12,1,3,7,14,22,1,3,8,13,24,30,1,3,7,14,24,30,42,1,
%T 3,8,12,26,32,43,61,1,3,7,13,24,33,47,63,71,1,3,8,14,24,31,43,66,72,
%U 88,1,3,7,13,22,30,47,60,73,83,108,1,3,8,12,24,32,43,66,71,90,117,126
%N Square array A(row,col) = (1/2) * (A255127(row,col+1) - A255127(row,col)): half of the first differences of each row of Ludic array.
%C The array A(row,col) is read by downwards antidiagonals as A(1,1), A(1,2), A(2,1), A(1,3), A(2,2), A(3,1), ...
%H Antti Karttunen, <a href="/A257258/b257258.txt">Table of n, a(n) for n = 1..10440; the first 144 antidiagonals of the array</a>
%F A(row,col) = (1/2) * (A255127(row,col+1) - A255127(row,col)).
%F A(row,col) = A257257(row,col)/2.
%e The top left corner of the array:
%e 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1
%e 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3
%e 7, 8, 7, 8, 7, 8, 7, 8, 7, 8, 7, 8, 7, 8, 7, 8
%e 12, 14, 13, 14, 12, 13, 14, 13, 12, 14, 13, 14, 12, 13, 14, 13
%e 22, 24, 24, 26, 24, 24, 22, 24, 26, 24, 24, 24, 22, 26, 24, 24
%e 30, 30, 32, 33, 31, 30, 32, 31, 30, 35, 30, 30, 31, 32, 30, 33
%e 42, 43, 47, 43, 47, 43, 41, 46, 44, 46, 44, 45, 45, 42, 45, 45
%e 61, 63, 66, 60, 66, 63, 65, 63, 60, 66, 64, 63, 65, 64, 63, 65
%e 71, 72, 73, 71, 73, 69, 75, 74, 70, 74, 73, 69, 75, 69, 75, 74
%e 88, 83, 90, 84, 88, 89, 85, 89, 85, 90, 87, 86, 88, 89, 88, 87
%e 108, 117, 113, 121, 114, 113, 120, 109, 117, 123, 110, 115, 117, 113, 117, 118
%e 126, 135, 127, 137, 129, 127, 129, 138, 131, 133, 129, 128, 132, 138, 132, 132
%e 137, 142, 134, 142, 152, 135, 141, 139, 147, 141, 141, 138, 141, 144, 146, 138
%e 154, 158, 157, 158, 160, 158, 156, 154, 162, 168, 158, 151, 158, 157, 161, 157
%e 180, 180, 177, 184, 180, 186, 185, 184, 176, 180, 190, 177, 185, 190, 176, 184
%e 206, 217, 212, 210, 213, 220, 213, 210, 216, 212, 211, 222, 212, 211, 215, 213
%e ...
%o (Scheme)
%o (define (A257258 n) (A257258bi (A002260 n) (A004736 n)))
%o (define (A257258bi row col) (* (/ 1 2) (- (A255127bi row (+ 1 col)) (A255127bi row col)))) ;; Code for A255127bi given in A255127.
%Y Column 1: A256483.
%Y Cf. A255127, A257257 (same array but with terms multiplied by 2).
%K nonn,tabl
%O 1,3
%A _Antti Karttunen_, Apr 29 2015