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A027422 Triangle T00, T10, T11, T20, T21, T22, etc. where Tmn = number of distinct products ij with m-n<=i,j<=m.

%I A027422 #15 Jul 08 2025 17:51:59
%S A027422 1,1,2,1,3,4,1,3,6,7,1,3,6,9,10,1,3,6,10,14,15,1,3,6,10,14,18,19,1,3,
%T A027422 6,10,15,20,25,26,1,3,6,10,15,20,25,30,31,1,3,6,10,15,20,26,31,36,37,
%U A027422 1,3,6,10,15,21,26,32,37,42,43,1,3,6,10,15,21,28,34,41,47,53,54,1,3,6
%N A027422 Triangle T00, T10, T11, T20, T21, T22, etc. where Tmn = number of distinct products ij with m-n<=i,j<=m.
%H A027422 R. J. Mathar, <a href="/A027422/b027422.txt">Table of n, a(n) for n = 0..1890</a>
%e A027422 1 ;
%e A027422 1 2 ;
%e A027422 1 3 4 ;
%e A027422 1 3 6 7 ;
%e A027422 1 3 6 9 10 ;
%e A027422 1 3 6 10 14 15 ;
%e A027422 1 3 6 10 14 18 19 ;
%e A027422 1 3 6 10 15 20 25 26 ;
%e A027422 1 3 6 10 15 20 25 30 31 ;
%e A027422 1 3 6 10 15 20 26 31 36 37 ;
%e A027422 1 3 6 10 15 21 26 32 37 42 43 ;
%e A027422 1 3 6 10 15 21 28 34 41 47 53 54 ;
%e A027422 1 3 6 10 15 21 27 34 40 47 53 59 60 ;
%p A027422 A027422 := proc(m,n)
%p A027422     local L,i,j ;
%p A027422     L := {};
%p A027422     for i from m-n to m do
%p A027422         for j from i to m do
%p A027422             L := L union {i*j};
%p A027422         end do:
%p A027422     end do:
%p A027422     nops(L);
%p A027422 end proc: # _R. J. Mathar_, May 06 2016
%Y A027422 Cf. A027384, A027421.
%K A027422 tabl,nonn,easy
%O A027422 0,3
%A A027422 _N. J. A. Sloane_
%E A027422 More terms from _Olivier Gérard_, Nov 15 1997