A352242 - OEIS

%I #10 Mar 09 2022 10:40:25

%S 7,52,19,189,112,37,496,351,196,61,1075,832,567,304,91,2052,1675,1264,

%T 837,436,127,3577,3024,2425,1792,1161,592,169,5824,5047,4212,3325,

%U 2416,1539,772,217,8991,7936,6811,5616,4375,3136,1971,976,271,13300,11907,10432,8869,7236,5575,3952,2457,1204,331

%N Regular triangle T(n,k) = (n-k)*(n^3-k^3) for n>=2 and 1 <= k <= n-1, read by rows.

%H Michael De Vlieger, <a href="/A352242/b352242.txt">Table of n, a(n) for n = 2..11176</a> (rows n = 2..150, flattened)

%e Triangle begins:

%e      7;

%e     52,   19;

%e    189,  112,   37;

%e    496,  351,  196,  61;

%e   1075,  832,  567, 304,  91;

%e   2052, 1675, 1264, 837, 436, 127;

%e   ...

%t Table[(n - k) (n^3 - k^3), {n, 2, 11}, {k, n - 1}] // Flatten (* _Michael De Vlieger_, Mar 09 2022 *)

%o (PARI) row(n) = vector(n-1, k, (n-k)*(n^3-k^3));

%Y Cf. A003215 (right diagonal), A138849 (left border).

%Y Cf. A352243, A352244.

%K nonn,tabl

%O 2,1

%A _Michel Marcus_, Mar 09 2022