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.

A240605 Total number of distinct sequences for the number of double occupancy in the underlying Fermion problem (see comment), i.e., the number of distinct hopping sequences (cf. A198761, A225823) in four-colored rooted trees with n nodes, starting and ending with the same coloring in two colors (cf. A198760, corresponding to zero double-occupancy).

Table of values

n a(n)
2 1
3 2
4 10
5 59
6 397
7 2878
8 21266
9 162732
10 1253128
11 9839212
12 77644825
13 620377508
14 4981522538
15 40351448045
16 328421827064
17 2690586461296
18 22139293490054
19 183106636176023
20 1520309861062921
21 12675106437486945
22 106033283581264574
23 890035798660219755

List of values

[1, 2, 10, 59, 397, 2878, 21266, 162732, 1253128, 9839212, 77644825, 620377508, 4981522538, 40351448045, 328421827064, 2690586461296, 22139293490054, 183106636176023, 1520309861062921, 12675106437486945, 106033283581264574, 890035798660219755]

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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