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A188127 Number of strictly increasing arrangements of 8 nonzero numbers in -(n+6)..(n+6) with sum zero 1
137, 484, 1398, 3528, 7970, 16547, 32035, 58595, 102113, 170844, 275878, 432018, 658432, 979785, 1427065, 2039067, 2863403, 3958322, 5393994, 7254686, 9640296, 12669003, 16479033, 21231771, 27113883, 34340884, 43159574, 53852210, 66739242 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Row 8 of A188122

LINKS

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

FORMULA

Empirical: a(n)=2*a(n-1)-a(n-3)-a(n-5)+a(n-6)-a(n-7)+a(n-9)+a(n-10)+a(n-12)-2*a(n-13)-2*a(n-16)+a(n-17)+a(n-19)+a(n-20)-a(n-22)+a(n-23)-a(n-24)-a(n-26)+2*a(n-28)-a(n-29).

Empirical: G.f. -x*(-137 -210*x -3284*x^12 -869*x^3 -1398*x^4 -2142*x^5 -2816*x^6 -3546*x^7 -4084*x^8 -4269*x^10 -3951*x^11 -2644*x^13 -1892*x^14 -1202*x^15 -768*x^16 -389*x^17 -202*x^18 -87*x^19 -5*x^20 +20*x^21 -26*x^22 +32*x^23 +5*x^24 +29*x^25 -9*x^26 -57*x^27 +31*x^28 -4356*x^9 -430*x^2) / ( (x^2-x+1) *(x^5-1) *(x^7-1) *(x^2+1) *(1+x+x^2)^2 *(1+x)^3 *(x-1)^6 ). - R. J. Mathar, Mar 21 2011

EXAMPLE

Some solutions for n=6

-12..-11..-12...-8..-10..-12...-9..-10...-6..-12...-8..-10..-12..-10..-12..-11

.-9..-10...-7...-7...-7..-11...-8...-8...-5...-9...-7...-6...-4...-8...-9...-7

.-8...-2...-6...-4...-4...-3...-7...-7...-2...-3...-3...-3...-3...-5...-7...-5

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

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

..7....3....5....4....5....4....6....7....2....4....3....2....3....5....5....8

..9....5...11....7...10...11...11....8....5...10....4....5....6....8....7....9

.10...12...12....8...11...12...12...11....6...11...11...12....7...12...10...12

CROSSREFS

Sequence in context: A142211 A142447 A142620 * A142813 A202083 A136080

Adjacent sequences:  A188124 A188125 A188126 * A188128 A188129 A188130

KEYWORD

nonn

AUTHOR

R. H. Hardin Mar 21 2011

STATUS

approved

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Last modified September 22 09:19 EDT 2017. Contains 292336 sequences.