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A141017 List of largest numbers of triangles with index of asymmetry (y=1) and index of obliqueness (z=0 or z=1). 0
1, 1, 2, 4, 7, 12, 23, 46, 89, 168, 311, 594, 1194, 2355, 4570, 8745, 16532, 32948, 65761, 129632, 252697, 487647, 936785, 1884892, 3754166, 7407451, 14489982, 28118751, 54868937, 110096666, 219129673, 432847116, 848952949, 1654022768 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

Triangle with index of asymmetry (y=1) and index of obliqueness (z=0) read by rows with recurrence G(n,k): G(n,0)=G(n+1,n+1)=1, G(n+2, n+1)=2, G(n+3, k)=G(n+1, k-1)+G(n+1, k)+G(n+2, k) for k:=1..(n+1).

Triangle with index of asymmetry (y=1) and index of obliqueness (z=1) read by rows with recurrence G(n,k): G(n, n)=G(n+1, 0)=1, G(n+2, 1)=2, G(n+3, k)=G(n+1, k-1)+G(n+1, k-2)+G(n+1, k-1) for k=2..(n+2).

LINKS

Table of n, a(n) for n=1..34.

FORMULA

a(n) = max(A140993(n,k), k=1..n). - R. J. Mathar, Apr 28 2010

EXAMPLE

Triangle (y=1, z=1) begins:

If 1, then largest number a(1)=1

If 1 1, then largest number a(2)=1

If 1 2 1, then largest number a(3)=2

If 1 4 2 1, then largest number a(4)=4

If 1 7 5 2 1, then largest number a(5)=7

If 1 12 11 5 2 1, then largest number a(6)=12

If 1 20 23 12 5 2 1, then largest number a(7)=23

If 1 33 46 28 12 5 2 1, then largest number a(8)=46

If 1 54 89 63 29 12 5 2 1, then largest number a(9)=89

CROSSREFS

Cf. A007318.

Sequence in context: A018080 A226160 A018181 * A190591 A027945 A079800

Adjacent sequences:  A141014 A141015 A141016 * A141018 A141019 A141020

KEYWORD

nonn

AUTHOR

Juri-Stepan Gerasimov, Jul 11 2008

EXTENSIONS

a(4) and offset corrected by Gary W. Adamson, Jul 11 2008

More terms from R. J. Mathar, Apr 28 2010

STATUS

approved

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Last modified May 19 14:36 EDT 2019. Contains 323395 sequences. (Running on oeis4.)