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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. 2
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, 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, 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 (list; table; graph; refs; listen; history; text; internal format)
OFFSET
0,3
LINKS
EXAMPLE
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 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 ;
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 10 15 21 27 34 40 47 53 59 60 ;
MAPLE
A027422 := proc(m, n)
local L, i, j ;
L := {};
for i from m-n to m do
for j from i to m do
L := L union {i*j};
end do:
end do:
nops(L);
end proc: # R. J. Mathar, May 06 2016
CROSSREFS
Sequence in context: A059663 A338367 A186975 * A135086 A210561 A210549
KEYWORD
tabl,nonn,easy
AUTHOR
EXTENSIONS
More terms from Olivier Gérard, Nov 15 1997
STATUS
approved

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Last modified March 19 07:04 EDT 2024. Contains 370953 sequences. (Running on oeis4.)