cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A200168 Number of -n..n arrays x(0..4) of 5 elements with nonzero sum and with zero through 4 differences all nonzero.

Original entry on oeis.org

2, 276, 2778, 15040, 52486, 145482, 336992, 695778, 1309052, 2298830, 3808116, 6034796, 9189086, 13554364, 19435742, 27212132, 37285690, 50170962, 66371288, 86532042, 111309444, 141482278, 177842124, 221369312, 272987306, 333851184
Offset: 1

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Author

R. H. Hardin Nov 13 2011

Keywords

Comments

Row 5 of A200165

Examples

			Some solutions for n=5
.-5....5...-3...-1...-5....3...-5...-3...-4....4....5....4...-1....1...-3....3
..5...-1...-5....4....1....4....5....4....1....1....2....5....3....4...-5....4
.-4....1....3...-5...-2...-4...-1...-3....4....3....5...-3....2....2....3...-2
..2...-5...-2....4....1....5....4...-5...-4....1...-1...-4....4...-1...-4...-3
..4...-3...-3...-5....3...-4....3...-3....5...-4....4....3....2....3...-1...-5
		

Formula

Empirical: a(n) = -a(n-1) -2*a(n-2) -a(n-3) -a(n-4) +a(n-5) +2*a(n-6) +3*a(n-7) +3*a(n-8) +3*a(n-9) +2*a(n-10) +2*a(n-11) +a(n-12) +a(n-13) -a(n-15) -a(n-16) -3*a(n-17) -2*a(n-18) -4*a(n-19) -3*a(n-20) -5*a(n-21) -4*a(n-22) -5*a(n-23) -3*a(n-24) -3*a(n-25) +3*a(n-28) +3*a(n-29) +5*a(n-30) +5*a(n-31) +6*a(n-32) +6*a(n-33) +5*a(n-34) +5*a(n-35) +3*a(n-36) +3*a(n-37) -3*a(n-40) -3*a(n-41) -5*a(n-42) -4*a(n-43) -5*a(n-44) -3*a(n-45) -4*a(n-46) -2*a(n-47) -3*a(n-48) -a(n-49) -a(n-50) +a(n-52) +a(n-53) +2*a(n-54) +2*a(n-55) +3*a(n-56) +3*a(n-57) +3*a(n-58) +2*a(n-59) +a(n-60) -a(n-61) -a(n-62) -2*a(n-63) -a(n-64) -a(n-65)