A220597 - cp's OEIS frontend

A220597 Number of ways to reciprocally link elements of an n X 3 array either to themselves or to exactly two horizontal, vertical and antidiagonal neighbors, without 3-loops.

n	a(n)
1	1
2	7
3	65
4	471
5	3469
6	25747
7	190425
8	1408823
9	10424813
10	77135267
11	570740149
12	4223043591
13	31247282909
14	231205914319
15	1710746473929
16	12658211881263
17	93661059763965
18	693020010391803
19	5127816575062977
20	37941909947454471

[1, 7, 65, 471, 3469, 25747, 190425, 1408823, 10424813, 77135267, 570740149, 4223043591, 31247282909, 231205914319, 1710746473929, 12658211881263, 93661059763965, 693020010391803, 5127816575062977, 37941909947454471]

cp's OEIS Frontend

A220597 Number of ways to reciprocally link elements of an n X 3 array either to themselves or to exactly two horizontal, vertical and antidiagonal neighbors, without 3-loops.

Table of values

List of values