A360373 Triangular array T read by rows related to the multiplication table.
1, 2, 4, 2, 3, 6, 9, 6, 3, 4, 8, 12, 16, 12, 8, 4, 5, 10, 15, 20, 25, 20, 15, 10, 5, 6, 12, 18, 24, 30, 36, 30, 24, 18, 12, 6, 7, 14, 21, 28, 35, 42, 49, 42, 35, 28, 21, 14, 7, 8, 16, 24, 32, 40, 48, 56, 64, 56, 48, 40, 32, 24, 16, 8, 9, 18, 27, 36, 45, 54, 63, 72, 81
Offset: 1
Examples
Table T(n, k) , n>=1 , 1<=k<=2*n-1. n = 1 : 1 ; n = 2 : 2, 4, 2 ; n = 3 : 3, 6, 9, 6, 3 ; n = 4 : 4, 8, 12, 16, 12, 8, 4 ; n = 5 : 5, 10, 15, 20, 25, 20, 15, 10, 5 ; n = 6 : 6, 12, 18, 24, 30, 36, 30, 24, 18, 12, 6 ; n = 7 : 7, 14, 21, 28, 35, 42, 49, 42, 35, 28, 21, 14, 7 ; n = 8 : 8, 16, 24, 32, 40, 48, 56, 64, 56, 48, 40, 32, 24, 16, 8 ; ...
Crossrefs
Programs
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Maple
T:= (n, k)-> n*min(k, 2*n-k): seq(seq(T(n,k), k=1..2*n-1), n=1..10); # Alois P. Heinz, Feb 04 2023