A228742 Number of arrays of the median of three adjacent elements of some length 7 0..n array.
28, 185, 696, 1943, 4504, 9191, 17088, 29589, 48436, 75757, 114104, 166491, 236432, 327979, 445760, 595017, 781644, 1012225, 1294072, 1635263, 2044680, 2532047, 3107968, 3783965, 4572516, 5487093, 6542200, 7753411, 9137408, 10712019
Offset: 1
Keywords
Examples
Some solutions for n=4 ..2..2..4..2..2..1..3..2..1..3..0..3..2..0..0..3 ..2..2..4..0..2..0..2..1..4..3..2..1..4..1..4..3 ..4..2..4..4..1..0..2..0..1..3..0..2..0..4..1..0 ..1..4..1..0..4..0..0..1..4..1..0..2..0..1..4..2 ..2..1..2..4..1..0..1..3..4..2..0..3..0..4..1..2
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Formula
Empirical: a(n) = (n+1)*(19*n^4+186*n^3+349*n^2+226*n+60)/60.
Empirical: G.f. -x*(-28-17*x-6*x^2+18*x^3-6*x^4+x^5) / (x-1)^6. - R. J. Mathar, Sep 02 2013
Comments