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!)
A070307 Number of n X n matrices with nonnegative integer entries such that every row sum equals 3. 2
1, 16, 1000, 160000, 52521875, 30840979456, 29509034655744, 42998169600000000, 90647430472564453125, 265599227914240000000000, 1047192117300356121695451136, 5410240907043328777415185924096, 35821862005173382840059779052734375, 298285661929377847941529600000000000000 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Indranil Ghosh, Table of n, a(n) for n = 1..160

FORMULA

a(n) = C(n+2, 3)^n = A000292(n)^n.

MATHEMATICA

Table[ Binomial[n + 2, 3]^n, {n, 1, 14}]

PROG

(PARI) a(n) = binomial(n+2, 3)^n; \\ Michel Marcus, Mar 10 2017

(Python)

import math

f=math.factorial

def C(n, r): return f(n)/ f(r)/ f(n-r)

def A070307(n): return C(n + 2, 3)**n # Indranil Ghosh, Mar 10 2017

CROSSREFS

Cf. A061718, A000292.

Sequence in context: A024301 A211090 A160012 * A159683 A197104 A067490

Adjacent sequences:  A070304 A070305 A070306 * A070308 A070309 A070310

KEYWORD

nonn

AUTHOR

Sharon Sela (sharonsela(AT)hotmail.com), May 10 2002

EXTENSIONS

More terms from Robert G. Wilson v, May 10 2002

More terms from Michel Marcus, Mar 10 2017

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 May 14 06:27 EDT 2021. Contains 343878 sequences. (Running on oeis4.)