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.

A356790 Table read by antidiagonals: T(n,k) (n >= 1, k >= 1) is the number of regions formed by straight line segments when connecting the k-1 points along the top side of a rectangle to each of the k-1 points along the bottom side that divide these sides into k equal parts, along with straight lines that directly connect the n-1 points along the left side to the diametrically opposite point on the right side that divide these sides into n equal parts.

Original entry on oeis.org

1, 2, 2, 6, 4, 3, 18, 10, 6, 4, 48, 24, 16, 8, 5, 106, 56, 34, 20, 10, 6, 216, 116, 70, 44, 26, 12, 7, 382, 228, 134, 84, 58, 30, 14, 8, 650, 396, 250, 152, 112, 60, 36, 16, 9, 1030, 666, 422, 272, 190, 112, 78, 40, 18, 10, 1564, 1048, 696, 448, 320, 196, 150, 84, 46, 20, 11
Offset: 1

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Examples

			The table begins:
1,  2,  6,  18,  48,  106, 216, 382, 650,  1030, 1564, 2258, 3210, 4386, 5926, ...
2,  4,  10, 24,  56,  116, 228, 396, 666,  1048, 1584, 2280, 3234, 4412, 5954, ...
3,  6,  16, 34,  70,  134, 250, 422, 696,  1082, 1622, 2322, 3280, 4462, 6008, ...
4,  8,  20, 44,  84,  152, 272, 448, 726,  1116, 1660, 2364, 3326, 4512, 6062, ...
5,  10, 26, 58,  112, 190, 320, 506, 794,  1194, 1748, 2462, 3434, 4630, 6190, ...
6,  12, 30, 60,  112, 196, 326, 512, 800,  1200, 1754, 2468, 3440, 4636, 6196, ...
7,  14, 36, 78,  150, 258, 418, 626, 936,  1358, 1934, 2670, 3664, 4882, 6464, ...
8,  16, 40, 84,  152, 256, 414, 632, 942,  1364, 1940, 2676, 3670, 4888, 6470, ...
9,  18, 46, 94,  172, 290, 468, 710, 1050, 1490, 2084, 2838, 3850, 5086, 6686, ...
10, 20, 50, 104, 188, 304, 480, 720, 1060, 1516, 2112, 2868, 3882, 5120, 6722, ...
11, 22, 56, 118, 218, 366, 586, 878, 1280, 1794, 2454, 3258, 4320, 5606, 7256, ...
12, 24, 60, 120, 208, 336, 518, 764, 1114, 1580, 2204, 2992, 4020, 5272, 6888, ...
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See the attached table for further terms.
		

Crossrefs

Formula

T(1,k) = A306302(k-2) + 2, k >= 2.
T(2,k) = 2*A355902(k-2) + 4 = A306302(k-2) + 2*k, k >= 2.
T(n,1) = n.
T(n,2) = 2n.
T(n,3) = A146951(n).