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A074878 Row sums of triangle in A074829. 6
1, 2, 6, 14, 32, 70, 150, 316, 658, 1358, 2784, 5678, 11534, 23356, 47178, 95110, 191440, 384854, 772902, 1550972, 3110306, 6234142 (list; graph; refs; listen; history; internal format)
OFFSET

1,2

COMMENTS

Contribution from Johannes W. Meijer (meijgia(AT)hotmail.com), Aug 15 2010: (Start)

An elephant sequence, see A175654. For the corner squares 16 A[5] vectors, with decimal values between 43 and 424, lead to this sequence. For the central square these vectors lead to the companion sequence A175657.

(End)

FORMULA

a(1)=1, a(2)=2, a(3)=6, a(n)=3*a(n-1)-a(n-2)-2*a(n-3) for n>3 . a(n)=3*2^(n-1)-2*F(n+1), F(n)=A000045(n) . G;f. x*(1-x+x^2)/(1-3*x+x^2+2*x^3) . - Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Sep 20 2006

a(1)=1, a(n)=2*[a(n-1)+F(n-2)] where the Fibonacci number F(n-2)=A000045(n-2) - Anton Vrba (antonvrba(AT)yahoo.com), Feb 06 2007

Contribution from Johannes W. Meijer (meijgia(AT)hotmail.com), Aug 15 2010: (Start)

a(n) = 3*2^n-2*F(n+2) with F(n)=A000045(n).

(End)

CROSSREFS

Sequence in context: A055292 A035592 A096238 * A065495 A131352 A051485

Adjacent sequences:  A074875 A074876 A074877 * A074879 A074880 A074881

KEYWORD

easy,nonn

AUTHOR

Joseph L. Pe (joseph_l_pe(AT)hotmail.com), Sep 30 2002

EXTENSIONS

More terms from Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Sep 20 2006

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Last modified February 17 02:31 EST 2012. Contains 205978 sequences.