login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A256411 Triangle read by rows: T(n,k) (1 <= k <= n) = number of ascendingly generated semigroups of order n with k generators. 1
1, 2, 8, 3, 37, 113, 4, 145, 1257, 3492, 5, 452, 9020, 67394, 183732, 6, 1374, 60826, 938194, 6398792, 17061118, 7, 3933, 356023, 30492722, 466578957, 3032145644, 7743056064 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..28.

Alex Bailey, Martin Finn-Sell, Robert Snocken, Subsemigroup, ideal and congruence growth of free semigroups, arXiv preprint arXiv:1409.2444, 2014

EXAMPLE

Triangle begins:

1,

2,8,

3,37,113,

4,145,1257,3492,

5,452,9020,67394,183732,

6,1374,60826,938194,6398792,17061118,

7,3933,356023,30492722,466578957,3032145644,7743056064,

...

CROSSREFS

Main diagonal is A023814. Column 2 is A256412.

Sequence in context: A292930 A126951 A282637 * A218609 A268491 A076588

Adjacent sequences:  A256408 A256409 A256410 * A256412 A256413 A256414

KEYWORD

nonn,tabl

AUTHOR

N. J. A. Sloane, Apr 03 2015

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified February 25 11:07 EST 2020. Contains 332231 sequences. (Running on oeis4.)