# [seqfan] Re: A193376 Tabl = 20 existing sequences

Olivier Gerard olivier.gerard at gmail.com
Mon Jul 25 14:20:37 CEST 2011

```On Mon, Jul 25, 2011 at 03:04, Ron Hardin <rhhardin at att.net> wrote:
> https://oeis.org/A193376
> T(n,k)=Number of ways to place any number of 2X1 tiles of k distinguishable
> colors into an nX1 grid
>
>
>
> Table starts
> ..1...1....1....1.....1.....1.....1......1......1......1......1......1......1
> ..2...3....4....5.....6.....7.....8......9.....10.....11.....12.....13.....14
> ..3...5....7....9....11....13....15.....17.....19.....21.....23.....25.....27
> ..5..11...19...29....41....55....71.....89....109....131....155....181....209
> ..8..21...40...65....96...133...176....225....280....341....408....481....560
> .13..43...97..181...301...463...673....937...1261...1651...2113...2653...3277
> .21..85..217..441...781..1261..1905...2737...3781...5061...6601...8425..10557
> .34.171..508.1165..2286..4039..6616..10233..15130..21571..29844..40261..53158
> .55.341.1159.2929..6191.11605.19951..32129..49159..72181.102455.141361.190399
> .89.683.2683.7589.17621.35839.66263.113993.185329.287891.430739.624493.881453

> Possibly interesting because various rows, columns and diagonals are 20 existing
> sequences.
>

Yes the first diagonal 1,3,7,29,96, ... for instance
would give a nice combinatorial model for  A171180
(whose author's formula does not seem right to me)

Olivier

```