The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A201874 Number of zero-sum -n..n arrays of 3 elements with first and second differences also in -n..n. 2
 3, 5, 15, 21, 27, 47, 57, 67, 97, 111, 125, 165, 183, 201, 251, 273, 295, 355, 381, 407, 477, 507, 537, 617, 651, 685, 775, 813, 851, 951, 993, 1035, 1145, 1191, 1237, 1357, 1407, 1457, 1587, 1641, 1695, 1835, 1893, 1951, 2101, 2163, 2225, 2385, 2451, 2517 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Row 3 of A201873. LINKS R. H. Hardin, Table of n, a(n) for n = 1..210 FORMULA Empirical: a(n) = a(n-1) +2*a(n-3) -2*a(n-4) -a(n-6) +a(n-7). Empirical g.f.: x*(3 + 2*x + x^2)*(1 + 3*x^2 - 2*x^3 + x^4) / ((1 - x)^3*(1 + x + x^2)^2). - Colin Barker, Feb 15 2018 EXAMPLE Some solutions for n=12: .-2....8...-2...-9....2..-10....9....1....0...-5...-3....5...-6...11....3....2 ..3...-4....0....1...-3....1....0....1...-3....4....0...-2....0...-1....4...-2 .-1...-4....2....8....1....9...-9...-2....3....1....3...-3....6..-10...-7....0 CROSSREFS Sequence in context: A063185 A208854 A165260 * A059528 A070079 A142717 Adjacent sequences: A201871 A201872 A201873 * A201875 A201876 A201877 KEYWORD nonn AUTHOR R. H. Hardin, Dec 06 2011 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified August 8 03:17 EDT 2024. Contains 375018 sequences. (Running on oeis4.)