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A337879
a(n) is the length of the n-th line segment to draw the squares of the Fibonacci spiral without lifting the pencil, including superpositions.
1
1, 1, 1, 2, 1, 2, 3, 2, 3, 5, 3, 5, 8, 5, 8, 13, 8, 13, 21, 13, 21, 34, 21, 34, 55, 34, 55, 89, 55, 89, 144, 89, 144, 233, 144, 233, 377, 233, 377, 610, 377, 610, 987, 610, 987, 1597, 987, 1597, 2584, 1597, 2584, 4181, 2584, 4181, 6765, 4181, 6765, 10946
OFFSET
1,4
COMMENTS
To draw the Fibonacci squares without lifting your pencil, go a(n) units and turn 90 degrees (same direction every time), and so on (see the animation).
As an array read by rows, with two columns, in which column 1 lists three copies of every nonzero term of A001906 in nondecreasing order, and the column 2 lists 1 together with three copies of every term > 1 of A001519 in nondecreasing order. - Omar E. Pol, Sep 29 2020
FORMULA
a(n) = Fibonacci(A008611(n+2)). - David A. Corneth, Sep 28 2020
G.f.: -x*(x^5+x^3+x^2+x+1)/(x^6+x^3-1). - Alois P. Heinz, Sep 29 2020
a(n) = a(n-3) + a(n-6) for n > 6. - Jinyuan Wang, Sep 30 2020
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Victor Kelly, Sep 22 2020
EXTENSIONS
More terms from Alois P. Heinz, Sep 29 2020
STATUS
approved