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
Offset: 1
Keywords
Examples
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
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)
Comments