A075652 - OEIS

A075652

Triangle read by rows in which the n-th row is an arithmetic progression of n terms with a common difference of n, and the first term is chosen the lowest possible so that no number appears twice.

%I #13 Nov 09 2016 12:55:02

%S 1,2,4,3,6,9,7,11,15,19,8,13,18,23,28,14,20,26,32,38,44,22,29,36,43,

%T 50,57,64,31,39,47,55,63,71,79,87,40,49,58,67,76,85,94,103,112,60,70,

%U 80,90,100,110,120,130,140,150,82,93,104,115,126,137,148,159,170,181,192,83

%N Triangle read by rows in which the n-th row is an arithmetic progression of n terms with a common difference of n, and the first term is chosen the lowest possible so that no number appears twice.

%H Ivan Neretin, <a href="/A075652/b075652.txt">Table of n, a(n) for n = 1..5050</a>

%e Triangle starts:

%e 1;

%e 2, 4;

%e 3, 6, 9;

%e 7, 11, 15, 19;

%e 8, 13, 18, 23, 28;

%e 14, 20, 26, 32, 38, 44;

%e 22, 29, 36, 43, 50, 57, 64;

%e ...

%t a = {1}; Do[d = Range[0, n - 1]*n; a = Join[a, Min[Complement[Range[Max@a + 1], Flatten@Outer[Plus, a, -d]]] + d], {n, 2, 12}]; a (* _Ivan Neretin_, Nov 09 2016 *)

%Y Cf. A075648, A075649, A075650, A075651.

%K nonn,tabl

%O 1,2

%A _Amarnath Murthy_, Oct 01 2002

%E More terms from _David Wasserman_, Jan 22 2005