OFFSET
0,3
COMMENTS
LINKS
Antti Karttunen, Table of n, a(n) for n = 0..64079
Dorin Andrica, Ovidiu Bagdasar, and George Cătălin Tųrcąs, On some new results for the generalised Lucas sequences, An. Şt. Univ. Ovidius Constanţa (Romania, 2021) Vol. 29, No. 1, 17-36.
FORMULA
EXAMPLE
a(9)=5 because there are 5 Lucas numbers <=9 (2,1,3,4 and 7).
MATHEMATICA
Join[{0}, Table[1+Floor[Log[GoldenRatio, (2*n+1)/2]], {n, 1, 100}]] (* G. C. Greubel, Sep 09 2018 *)
PROG
(PARI)
A102460(n) = { my(u1=1, u2=3, old_u1); if(n<=2, sign(n), while(n>u2, old_u1=u1; u1=u2; u2=old_u1+u2); (u2==n)); };
\\ Or just as:
c=0; for(n=0, 123, c += A102460(n); print1(c, ", ")); \\ Antti Karttunen, May 13 2018
(Magma) [0] cat [1+Floor(Log((2*n+1)/2)/Log((1+Sqrt(5))/2)): n in [1..100]]; // G. C. Greubel, Sep 09 2018
(Python)
from itertools import count, islice
def A130245_gen(): # generator of terms
yield from (0, 1, 2)
a, b = 3, 4
for i in count(3):
yield from (i, )*(b-a)
a, b = b, a+b
CROSSREFS
KEYWORD
nonn
AUTHOR
Hieronymus Fischer, May 19 2007, Jul 02 2007
STATUS
approved