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A190112

Number of 2:3:sqrt(13) proportioned triangles on a (n+1)X(n+1) grid.

0, 0, 16, 48, 120, 248, 440, 736, 1152, 1720, 2464, 3440, 4672, 6192, 8080, 10344, 13040, 16264, 20024, 24376, 29456, 35248, 41832, 49360, 57808, 67280, 77936, 89760, 102840, 117392, 133376, 150888, 170184, 191200, 214048, 239016, 266024, 295184

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

OFFSET

1,3

COMMENTS

Diagonal of A190113

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..99

FORMULA

Empirical: a(n) = a(n-1) +2*a(n-3) -2*a(n-4) -a(n-6) +a(n-7) +a(n-9) -a(n-10) -2*a(n-12) +3*a(n-13) -a(n-14) +a(n-15) -3*a(n-16) +2*a(n-17) +a(n-19) -a(n-20) -a(n-22) +a(n-23) +2*a(n-25) -2*a(n-26) -a(n-28) +a(n-29)

EXAMPLE

Some solutions for n=5

..2..1....1..0....3..5....3..2....3..0....1..5....0..5....3..3....4..2....2..3

..2..4....1..3....3..2....0..5....3..3....1..3....0..3....0..3....2..2....2..5

..4..1....3..0....5..5....1..0....5..0....4..5....3..5....3..1....4..5....5..3

CROSSREFS

Sequence in context: A098322 A175164 A331772 * A211576 A211590 A211584

Adjacent sequences: A190109 A190110 A190111 * A190113 A190114 A190115

KEYWORD

nonn

AUTHOR

R. H. Hardin, May 04 2011

STATUS

approved

URL: https://oeis.org/A190112

⇱ A190112 - OEIS