A214542 - OEIS

A214542

Number of 4X4X4 triangular 0..n arrays with no element lying outside the (possibly reversed) range delimited by its sw and se neighbors, and every horizontal row having the same average value

2, 93, 344, 1181, 3198, 7801, 16752, 33605, 62766, 111653, 189264, 309453, 488806, 751289, 1124676, 1647473, 2364174, 3333765, 4623132, 6319045, 8519174, 11346717, 14938900, 19465789, 25115826, 32118473, 40725436, 51239465, 63991794, 79374993

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

COMMENTS

Row 4 of A214540

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..130

FORMULA

Empirical: a(n) = a(n-1) +a(n-2) +a(n-3) -3*a(n-5) -2*a(n-6) -2*a(n-7) +4*a(n-8) +3*a(n-9) +2*a(n-10) -a(n-11) -3*a(n-12) -a(n-13) -a(n-14) +4*a(n-15) -a(n-16) -a(n-17) -3*a(n-18) -a(n-19) +2*a(n-20) +3*a(n-21) +4*a(n-22) -2*a(n-23) -2*a(n-24) -3*a(n-25) +a(n-27) +a(n-28) +a(n-29) -a(n-30)

EXAMPLE

Some solutions for n=4

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

....2.4......3.3......3.1......2.0......2.2......2.2......1.3......2.0

...2.4.3....2.3.4....3.2.1....1.2.0....2.2.2....1.4.1....1.4.1....2.1.0

..3.2.4.3..2.3.3.4..0.3.1.4..0.2.2.0..1.2.3.2..1.4.1.2..1.4.2.1..3.1.0.0

CROSSREFS

Sequence in context: A348852 A365852 A042057 * A137322 A239006 A248627

Adjacent sequences: A214539 A214540 A214541 * A214543 A214544 A214545

KEYWORD

nonn

AUTHOR

R. H. Hardin Jul 20 2012

STATUS

approved