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!)
A321777 Number of compositions of n into parts with distinct multiplicities and with exactly seven parts. 2
1, 7, 28, 42, 168, 238, 280, 428, 595, 595, 826, 910, 1078, 1232, 1716, 1498, 2023, 2093, 2450, 2450, 2996, 3228, 3626, 3710, 4193, 4263, 4998, 4928, 5916, 5838, 6426, 6510, 7371, 7455, 8316, 8464, 9198, 9268, 10318, 10248, 11319, 11473, 12524, 12460, 13636 (list; graph; refs; listen; history; text; internal format)
OFFSET

7,2

LINKS

Alois P. Heinz, Table of n, a(n) for n = 7..1000

FORMULA

Conjectures from Colin Barker, Dec 11 2018: (Start)

G.f.: x^7*(1 + 8*x + 36*x^2 + 78*x^3 + 245*x^4 + 475*x^5 + 719*x^6 + 1069*x^7 + 1419*x^8 + 1539*x^9 + 1645*x^10 + 1478*x^11 + 1100*x^12 + 708*x^13 + 505*x^14) / ((1 - x)^3*(1 + x)^2*(1 - x + x^2)*(1 + x^2)*(1 + x + x^2)*(1 + x + x^2 + x^3 + x^4)*(1 + x + x^2 + x^3 + x^4 + x^5 + x^6)).

a(n) = -a(n-1) - a(n-2) - a(n-3) + a(n-5) + 2*a(n-6) + 3*a(n-7) + 3*a(n-8) + 2*a(n-9) + a(n-10) - a(n-11) - 2*a(n-12) - 3*a(n-13) - 3*a(n-14) - 2*a(n-15) - a(n-16) + a(n-18) + a(n-19) + a(n-20) + a(n-21) for n>27.

(End)

CROSSREFS

Column k=7 of A242887.

Sequence in context: A155712 A015817 A103253 * A269451 A139607 A068206

Adjacent sequences:  A321774 A321775 A321776 * A321778 A321779 A321780

KEYWORD

nonn

AUTHOR

Alois P. Heinz, Nov 18 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 June 22 19:28 EDT 2021. Contains 345388 sequences. (Running on oeis4.)