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A212532 Number of nondecreasing sequences of n 1..4 integers with every element dividing the sequence sum. 1
4, 4, 7, 10, 15, 15, 24, 29, 39, 45, 57, 65, 83, 92, 111, 127, 149, 163, 193, 213, 245, 270, 305, 333, 378, 408, 455, 496, 547, 587, 650, 697, 763, 819, 889, 949, 1033, 1096, 1183, 1261, 1353, 1431, 1539, 1625, 1737, 1836, 1953, 2057, 2192, 2300, 2439, 2566, 2711 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 4 of A212536.

LINKS

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

FORMULA

Empirical: a(n) = a(n-1) + a(n-2) - a(n-4) - a(n-5) + a(n-6) + a(n-12) - a(n-13) - a(n-14) + a(n-16) + a(n-17) - a(n-18).

Empirical g.f.: x*(4 - x^2 - x^3 + 2*x^4 - 2*x^5 + x^6 + 3*x^7 + 4*x^8 - 3*x^9 - 3*x^10 + x^11 + x^12 - x^13 + 2*x^15 - x^17) / ((1 - x)^4*(1 + x)^2*(1 - x + x^2)*(1 + x^2)*(1 + x + x^2)^2*(1 - x^2 + x^4)). - Colin Barker, Jul 20 2018

EXAMPLE

Some solutions for n=8:

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

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

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

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

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

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

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

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

CROSSREFS

Cf. A212536.

Sequence in context: A185670 A011981 A238131 * A109544 A187893 A293678

Adjacent sequences:  A212529 A212530 A212531 * A212533 A212534 A212535

KEYWORD

nonn

AUTHOR

R. H. Hardin, May 20 2012

STATUS

approved

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Last modified September 20 08:13 EDT 2019. Contains 327214 sequences. (Running on oeis4.)