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!)
A300589 a(n) = A300617(n) / (n*(n+1)/2) for n>=1. 2
1, 1, 5, 55, 1025, 28638, 1117831, 58157100, 3895841625, 327054041995, 33660663702514, 4170641243258042, 612634528823952155, 105303950053511041900, 20943400410601239618360, 4772694556432364600596272, 1235587041134996933696367753, 360653856192923791041427500825, 117894515649092645422159124253775, 42901062533218086978322192560871705 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

It is conjectured that this sequence consists entirely of integers.

O.g.f. G(x) of A300617 satisfies: [x^n] exp(n*G(x)) = n^2 * [x^(n-1)] exp(n*G(x)) for n>=1.

LINKS

Paul D. Hanna, Table of n, a(n) for n = 1..300

PROG

(PARI) {a(n) = my(A=[1]); for(i=1, n+1, A=concat(A, 0); V=Vec(Ser(A)^(#A-1)); A[#A] = ((#A-1)^2*V[#A-1] - V[#A])/(#A-1) ); polcoeff( log(Ser(A)), n) / (n*(n+1)/2)}

for(n=1, 20, print1(a(n), ", "))

CROSSREFS

Cf. A300617, A300616.

Sequence in context: A266481 A006150 A140049 * A130031 A336289 A119399

Adjacent sequences:  A300586 A300587 A300588 * A300590 A300591 A300592

KEYWORD

nonn

AUTHOR

Paul D. Hanna, Mar 10 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 16 07:19 EDT 2021. Contains 347469 sequences. (Running on oeis4.)