login
This site is supported by donations to The OEIS Foundation.

 

Logo

Please make a donation to keep the OEIS running. We are now in our 55th year. In the past year we added 12000 new sequences and reached 8000 citations (which often say "discovered thanks to the OEIS"). We need to raise money to hire someone to manage submissions, which would reduce the load on our editors and speed up editing.
Other ways to donate

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A277407 a(n) = A277406(n)/(n+1). 3
1, 1, 3, 19, 220, 4196, 120876, 4915212, 268194816, 18903020544, 1671209210880, 181064295924480, 23589442167333120, 3638090042721918720, 655483159341216541440, 136420837710333144595200, 32478481518550347674419200, 8770206330674425311097651200, 2666047809138871800854163456000, 906320525390421790143785781657600, 342508343836409428996994343026688000 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

COMMENTS

A277406(n) equals the sum of all permutations of compositions of functions (1 + k*x) for k=1..n, evaluated at x=1.

LINKS

Table of n, a(n) for n=0..20.

FORMULA

a(n) = 1/(n+1) * Sum_{k=0..n} k!*(n-k)! * Sum_{i=0..n-k+1} (-1)^(n-i+1) * Stirling2(i,n-k+1) * Stirling1(n+1,i)).

PROG

(PARI) {a(n) = 1/(n+1) * sum(k=0, n, k!*(n-k)! * sum(i=0, n-k+1, (-1)^(n-i+1) * stirling(i, n-k+1, 2) * stirling(n+1, i, 1)))}

for(n=0, 20, print1(a(n), ", "))

CROSSREFS

Cf. A277405, A277406.

Sequence in context: A001833 A001035 A267634 * A271587 A217906 A166380

Adjacent sequences:  A277404 A277405 A277406 * A277408 A277409 A277410

KEYWORD

nonn

AUTHOR

Paul D. Hanna, Oct 16 2016

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 December 5 23:39 EST 2019. Contains 329784 sequences. (Running on oeis4.)