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A189321 Number of nondecreasing arrangements of n+2 numbers in 0..4 with the last equal to 4 and each after the second equal to the sum of one or two of the preceding four. 1
7, 12, 20, 32, 49, 70, 94, 120, 148, 178, 210, 244, 280, 318, 358, 400, 444, 490, 538, 588, 640, 694, 750, 808, 868, 930, 994, 1060, 1128, 1198, 1270, 1344, 1420, 1498, 1578, 1660, 1744, 1830, 1918, 2008, 2100, 2194, 2290, 2388, 2488, 2590, 2694, 2800, 2908 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 4 of A189326.

LINKS

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

FORMULA

Empirical: a(n) = n^2 + 11*n - 32 for n>5.

Empirical g.f.: x*(7 - 9*x + 5*x^2 + x^3 + x^4 - x^5 - x^6 - x^7) / (1 - x)^3. - Colin Barker, May 02 2018

EXAMPLE

Some solutions for n=3:

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

..3....2....4....4....3....2....3....1....2....4....2....2....2....1....2....4

..4....2....4....4....3....4....3....2....3....4....3....2....2....2....2....4

..4....2....4....4....4....4....3....2....3....4....4....2....3....3....2....4

..4....4....4....4....4....4....4....4....4....4....4....4....4....4....4....4

CROSSREFS

Cf. A189326.

Sequence in context: A271988 A071247 A025006 * A273072 A273147 A272845

Adjacent sequences:  A189318 A189319 A189320 * A189322 A189323 A189324

KEYWORD

nonn

AUTHOR

R. H. Hardin, Apr 20 2011

STATUS

approved

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Last modified June 15 17:43 EDT 2019. Contains 324142 sequences. (Running on oeis4.)