

A270925


Nearest integer to absolute value of the function f(n) where f(n) is the derivative of F(n) = ((1/2+sqrt(5)/2)^n(1/2sqrt(5)/2)^n)/sqrt(5) with respect to n.


0



1, 1, 1, 1, 2, 2, 4, 6, 10, 16, 26, 43, 69, 112, 181, 294, 475, 768, 1243, 2012, 3255, 5267, 8523, 13790, 22313, 36103, 58416, 94519, 152934, 247453, 400387, 647841, 1048228, 1696069, 2744297, 4440365, 7184662, 11625027, 18809689, 30434716, 49244405, 79679122, 128923527, 208602649, 337526177
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OFFSET

0,5


COMMENTS

F(n) is the Fibonacci(n) for integer n.
Since F(n) is the sum of F(n1) and F(n2), the derivative of F(n) is simply the sum of the derivatives of F(n1) and F(n2). So sum of the two consecutive terms is generally equal to next term of this sequence.


LINKS

Table of n, a(n) for n=0..44.


PROG

(PARI) f(n) = ((sqrt(5)1)^n*(log(1)log(2)+log(sqrt(5)1))*(1)^n+(1+sqrt(5))^n*(log(2)log(sqrt(5)+1)))/(sqrt(5)*2^n);
a(n) = round(abs(f(n)));


CROSSREFS

Cf. A000045.
Sequence in context: A055389 A163733 A198834 * A084202 A300865 A053637
Adjacent sequences: A270922 A270923 A270924 * A270926 A270927 A270928


KEYWORD

nonn


AUTHOR

Altug Alkan, Apr 05 2016


STATUS

approved



