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.

A271270 Number of set partitions of [n] such that for each pair of consecutive blocks (b,b+1) at least one pair of consecutive numbers (i,i+1) exists with i member of b and i+1 member of b+1.

Table of values

n a(n)
0 1
1 1
2 2
3 5
4 14
5 43
6 145
7 536
8 2157
9 9371
10 43630
11 216397
12 1137703
13 6313675
14 36848992
15 225464838
16 1442216870
17 9620746697
18 66781675113
19 481413175433
20 3597627996006
21 27825925290597
22 222422033403527
23 1834910286704787
24 15603508329713182
25 136616625732498989

List of values

[1, 1, 2, 5, 14, 43, 145, 536, 2157, 9371, 43630, 216397, 1137703, 6313675, 36848992, 225464838, 1442216870, 9620746697, 66781675113, 481413175433, 3597627996006, 27825925290597, 222422033403527, 1834910286704787, 15603508329713182, 136616625732498989]

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

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