login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A322798 Number of compositions (ordered partitions) of n into hexagonal numbers (A000384). 6
1, 1, 1, 1, 1, 1, 2, 3, 4, 5, 6, 7, 9, 12, 16, 22, 29, 37, 47, 60, 77, 101, 133, 174, 226, 292, 376, 486, 632, 823, 1072, 1394, 1808, 2342, 3036, 3939, 5116, 6648, 8636, 11211, 14548, 18875, 24493, 31795, 41283, 53604, 69594, 90338, 117251, 152184, 197540 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,7

LINKS

Alois P. Heinz, Table of n, a(n) for n = 0..8828

Eric Weisstein's World of Mathematics, Hexagonal Number

Index entries for sequences related to compositions

FORMULA

G.f.: 1/(1 - Sum_{k>=1} x^(k*(2*k-1))).

MAPLE

h:= proc(n) option remember; `if`(n<1, 0, (t->

      `if`(t*(2*t-1)>n, t-1, t))(1+h(n-1)))

    end:

a:= proc(n) option remember; `if`(n=0, 1,

      add(a(n-i*(2*i-1)), i=1..h(n)))

    end:

seq(a(n), n=0..60);  # Alois P. Heinz, Dec 28 2018

MATHEMATICA

nmax = 50; CoefficientList[Series[1/(1 - Sum[x^(k (2 k - 1)), {k, 1, nmax}]), {x, 0, nmax}], x]

CROSSREFS

Cf. A000384, A006456, A023361, A181324, A278949, A279279, A322799, A322800.

Sequence in context: A005708 A322853 A322801 * A085793 A281809 A143286

Adjacent sequences:  A322795 A322796 A322797 * A322799 A322800 A322801

KEYWORD

nonn

AUTHOR

Ilya Gutkovskiy, Dec 26 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 | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified August 13 16:07 EDT 2022. Contains 356107 sequences. (Running on oeis4.)