A257258 - OEIS

%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