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 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

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