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A245999 Number of length 4+2 0..n arrays with no pair in any consecutive three terms totalling exactly n 1
2, 26, 396, 2196, 9582, 29790, 80504, 185192, 391290, 753570, 1371972, 2352636, 3877286, 6128486, 9405552, 13997520, 20363634, 28934442, 40377980, 55306340, 74651742, 99252846, 130367976, 169112376, 217138922, 275894450, 347501364 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Row 4 of A245995

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..210

FORMULA

Empirical: a(n) = 3*a(n-1) +a(n-2) -11*a(n-3) +6*a(n-4) +14*a(n-5) -14*a(n-6) -6*a(n-7) +11*a(n-8) -a(n-9) -3*a(n-10) +a(n-11).

Empirical: G.f.: -2*x*(1 +10*x +158*x^2 +502*x^3 +1436*x^4 +1510*x^5 +1498*x^6 +474*x^7 +171*x^8) / ( (1+x)^4*(x-1)^7 ). - R. J. Mathar, Aug 10 2014

EXAMPLE

Some solutions for n=8

..1....2....1....3....2....0....0....1....1....0....4....0....2....5....5....3

..4....7....3....2....0....2....2....5....1....7....1....2....2....2....2....7

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

..6....5....1....4....2....8....4....7....8....5....3....4....7....8....7....5

..8....0....5....0....2....1....8....7....4....4....6....1....4....5....0....2

..4....1....6....1....7....8....7....4....6....7....1....1....7....5....6....2

CROSSREFS

Sequence in context: A096233 A126673 A057351 * A285026 A137100 A228411

Adjacent sequences:  A245996 A245997 A245998 * A246000 A246001 A246002

KEYWORD

nonn

AUTHOR

R. H. Hardin, Aug 09 2014

STATUS

approved

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Last modified April 6 12:08 EDT 2020. Contains 333273 sequences. (Running on oeis4.)