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A189328 Number of nondecreasing arrangements of 5 numbers in 0..n with the last equal to n and each after the second equal to the sum of one or two of the preceding four. 1
2, 8, 11, 20, 21, 36, 31, 49, 42, 63, 51, 79, 60, 93, 72, 105, 80, 125, 89, 133, 104, 149, 109, 168, 117, 178, 135, 190, 138, 213, 147, 219, 166, 234, 166, 257, 176, 263, 197, 274, 196, 303, 205, 304, 227, 319, 225, 346, 234, 347, 259, 360, 254, 392, 262, 389, 290, 404 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Row 3 of A189326.

LINKS

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

FORMULA

Empirical: a(n) = -3*a(n-1) -5*a(n-2) -5*a(n-3) -2*a(n-4) +3*a(n-5) +8*a(n-6) +10*a(n-7) +8*a(n-8) +3*a(n-9) -2*a(n-10) -5*a(n-11) -5*a(n-12) -3*a(n-13) -a(n-14).

Empirical g.f.: x*(2 + 14*x + 45*x^2 + 103*x^3 + 180*x^4 + 264*x^5 + 326*x^6 + 350*x^7 + 322*x^8 + 258*x^9 + 173*x^10 + 97*x^11 + 40*x^12 + 11*x^13) / ((1 - x)^2*(1 + x)^2*(1 + x^2)*(1 + x + x^2)^2*(1 + x + x^2 + x^3 + x^4)). - Colin Barker, May 02 2018

EXAMPLE

All solutions for n=3:

..1....1....1....1....0....1....3....0....2....1....1

..2....2....3....2....1....1....3....3....3....1....1

..2....2....3....3....1....2....3....3....3....2....1

..3....2....3....3....2....3....3....3....3....2....2

..3....3....3....3....3....3....3....3....3....3....3

CROSSREFS

Cf. A189326.

Sequence in context: A074263 A295070 A009420 * A090746 A234924 A174114

Adjacent sequences:  A189325 A189326 A189327 * A189329 A189330 A189331

KEYWORD

nonn

AUTHOR

R. H. Hardin, Apr 20 2011

STATUS

approved

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Last modified November 14 22:42 EST 2018. Contains 317221 sequences. (Running on oeis4.)