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A115338 a(n)=F([sqrt(n)]), where [k]=integer part of k and F(n) is the Fibonacci sequence. 0
0, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 3, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 34, 34, 34, 34, 34 (list; graph; refs; listen; history; internal format)
OFFSET

0,10

REFERENCES

D. Wells, The Penguin Dictionary of Curious and Interesting Numbers. Middlesex, England: Penguin Books, p. 62, 1986.

FORMULA

Since F(n) = nint((phi^n)/(sqrt(5))) where nint is the nearest integer function and phi is (1 + sqrt 5 )/2 = A001622 we have a(n) = nint((phi^[sqrt(n)])/(sqrt(5))). - Jonathan Vos Post (jvospost3(AT)gmail.com), Mar 08 2006

a(n) = F([sqrt(n)]). a(n) = A000045(A000196(n)). a(n) = nint((phi^[sqrt(n)])/(sqrt(5))).

EXAMPLE

a(143) = F([Sqrt(143)]) = F([11.958]) = F(11) = 89, a(144) = F([Sqrt(144)]) = F([12]) = F(12) = 144, a(145) = F([Sqrt(145)]) = F([12.042]) = F(12) = 144.

MATHEMATICA

Table[Fibonacci[Floor[Sqrt[n]]], {n, 0, 70}] - Stefan Steinerberger (stefan.steinerberger(AT)gmail.com)

CROSSREFS

Equals A000045(A000196(n)).

Cf. A000045, A000196, A001622.

Sequence in context: A134914 A204164 A180447 * A133877 A132270 A195174

Adjacent sequences:  A115335 A115336 A115337 * A115339 A115340 A115341

KEYWORD

easy,nonn

AUTHOR

Giuseppe Coppoletta (gcoverest-11(AT)yahoo.fr), Mar 06 2006

EXTENSIONS

More terms from Stefan Steinerberger (stefan.steinerberger(AT)gmail.com) and Jonathan Vos Post (jvospost3(AT)gmail.com), Mar 08 2006

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Last modified February 17 19:04 EST 2012. Contains 206081 sequences.