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A188239 Number of nondecreasing arrangements of 6 numbers in -(n+4)..(n+4) with sum zero and not more than two numbers equal. 1
245, 527, 1019, 1818, 3047, 4859, 7435, 10994, 15791, 22121, 30323, 40782, 53931, 70257, 90301, 114662, 143999, 179037, 220565, 269444, 326607, 393061, 469893, 558272, 659449, 774765, 905649, 1053624, 1220309, 1407423, 1616785, 1850320 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Row 6 of A188236.

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..200

FORMULA

Empirical: a(n) = 3*a(n-1) - 2*a(n-2) - a(n-3) + 2*a(n-5) - a(n-6) - a(n-7) + 2*a(n-8) - a(n-10) - 2*a(n-11) + 3*a(n-12) - a(n-13).

Empirical g.f.: x*(245 - 208*x - 72*x^2 + 60*x^3 + 158*x^4 - 117*x^5 - 39*x^6 + 188*x^7 - 42*x^8 - 140*x^9 - 110*x^10 + 263*x^11 - 98*x^12) / ((1 - x)^6*(1 + x)*(1 + x + x^2)*(1 + x + x^2 + x^3 + x^4)). - Colin Barker, Apr 27 2018

EXAMPLE

Some solutions for n=4:

.-8...-7...-7...-6...-4...-8...-4...-7...-5...-7...-4...-6...-7...-5...-7...-7

.-2...-6...-6...-4...-4...-4...-4...-6...-3...-4...-3...-5...-6...-2...-1...-7

.-1...-1...-6...-4...-1...-2....0...-6...-1...-1...-2...-4...-4...-2....0...-2

..3...-1....6....3...-1....4....1....5....1....2...-1....3....5....1....1....4

..3....7....6....3....4....4....2....7....2....5....4....5....6....3....1....5

..5....8....7....8....6....6....5....7....6....5....6....7....6....5....6....7

CROSSREFS

Cf. A188236.

Sequence in context: A129210 A137521 A257781 * A132830 A350421 A236887

Adjacent sequences:  A188236 A188237 A188238 * A188240 A188241 A188242

KEYWORD

nonn

AUTHOR

R. H. Hardin, Mar 24 2011

STATUS

approved

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Last modified August 11 00:55 EDT 2022. Contains 356046 sequences. (Running on oeis4.)