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!)
A317447 Number of permutations of [n] whose lengths of increasing runs are distinct prime numbers. 6
1, 0, 1, 1, 0, 19, 0, 41, 110, 70, 13696, 1, 44796, 155, 411064, 2122802, 251746, 1057634441, 4404368, 25043183, 44848672, 19725545894, 106293316, 307873058001, 50194102, 8305023165502, 65808841818130, 33715371370134, 115625740201672616, 78940089764191 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,6

LINKS

Alois P. Heinz, Table of n, a(n) for n = 0..100

MAPLE

g:= (n, s)-> `if`(n in s or not (n=0 or isprime(n)), 0, 1):

b:= proc(u, o, t, s) option remember; `if`(u+o=0, g(t, s),

      `if`(g(t, s)=1, add(b(u-j, o+j-1, 1, s union {t})

       , j=1..u), 0)+ add(b(u+j-1, o-j, t+1, s), j=1..o))

    end:

a:= n-> b(n, 0$2, {}):

seq(a(n), n=0..40);

CROSSREFS

Cf. A000040, A317131, A317444, A317445, A317446, A317448.

Sequence in context: A240952 A221749 A055967 * A202582 A292605 A040365

Adjacent sequences:  A317444 A317445 A317446 * A317448 A317449 A317450

KEYWORD

nonn

AUTHOR

Alois P. Heinz, Jul 28 2018

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 September 30 05:03 EDT 2020. Contains 337435 sequences. (Running on oeis4.)