cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A334922 Square array T(n,k) = ((3/2)*n*k + (1/2)*A319929(n,k))/2, n >= 1, k >= 1, read by antidiagonals.

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%I A334922 #30 Aug 03 2020 00:22:21
%S A334922 1,2,2,3,3,3,4,5,5,4,5,6,8,6,5,6,8,10,10,8,6,7,9,13,12,13,9,7,8,11,15,
%T A334922 16,16,15,11,8,9,12,18,18,21,18,18,12,9,10,14,20,22,24,24,22,20,14,10,
%U A334922 11,15,23,24,29,27,29,24,23,15,11
%N A334922 Square array T(n,k) = ((3/2)*n*k + (1/2)*A319929(n,k))/2, n >= 1, k >= 1, read by antidiagonals.
%C A334922 T(n,k) is commutative, associative, has identity element 1 and has 0. Also it is distributive except when an even number is partitioned into two odd numbers. Thus it has a multiplicative structure similar to that of A319929, A322630, A322744 and A327259 except that T(odd,odd) is not always odd, T(even,even) is not always even and T(odd,even) is not always even.
%C A334922 T(n,k) is in the same form as the supplementary arrays of A327263 called U(i;n,k). Here (and in A334923) i is being incremented by 1/2. When i is incremented by 1/4 or less, array values cease to be all integers, although all of the multiplication rules still hold.
%H A334922 David Lovler, <a href="/A334922/b334922.txt">Table of n, a(n) for n = 1..465</a>
%F A334922 T(n,k) = 3*floor(n/2)*floor(k/2) + A319929(n,k).
%F A334922 T(n,k) = (A322630(n,k) + n*k)/2.
%F A334922 T(n,k) = (A319929 + A322744(n,k))/2.
%F A334922 T(n,k) = 2*n*k - A334923(n,k).
%e A334922 Array begins:
%e A334922 1   2   3   4   5   6   7   8   9  10 ...
%e A334922 2   3   5   6   8   9  11  12  14  15 ...
%e A334922 3   5   8  10  13  15  18  20  23  25 ...
%e A334922 4   6  10  12  16  18  22  24  28  30 ...
%e A334922 5   8  13  16  21  24  29  32  37  40 ...
%e A334922 6   9  15  18  24  27  33  36  42  45 ...
%e A334922 7  11  18  22  29  33  40  44  51  55 ...
%e A334922 8  12  20  24  32  36  44  48  56  60 ...
%e A334922 9  14  23  28  37  42  51  56  65  70 ...
%e A334922 10 15  25  30  40  45  55  60  70  75 ...
%e A334922 ...
%t A334922 Table[Function[n, ((3/2)*n*k + (1/2)*If[OddQ@ n, If[OddQ@ k, n + k - 1, k], If[OddQ@ k, n, 0]])/2][m - k + 1], {m, 11}, {k, m}] // Flatten (* _Michael De Vlieger_, Jun 23 2020 *)
%Y A334922 Cf. A319929, A322630, A322744, A327259, A327263, A334923.
%K A334922 nonn,tabl
%O A334922 1,2
%A A334922 _David Lovler_, May 16 2020