A072683 - OEIS

A072683

Numbers k such that the last digit of F(k) is 3 where F(k) is the k-th Fibonacci number.

4, 7, 13, 26, 44, 46, 47, 53, 64, 67, 73, 86, 104, 106, 107, 113, 124, 127, 133, 146, 164, 166, 167, 173, 184, 187, 193, 206, 224, 226, 227, 233, 244, 247, 253, 266, 284, 286, 287, 293, 304, 307, 313, 326, 344, 346, 347, 353, 364, 367, 373, 386, 404, 406, 407

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OFFSET

1,1

COMMENTS

Numbers that are congruent to {4, 7, 13, 26, 44, 46, 47, 53} mod 60. - Amiram Eldar, Jan 01 2022

LINKS

Table of n, a(n) for n=1..55.

Index entries for linear recurrences with constant coefficients, signature (1,0,0,0,0,0,0,1,-1).

FORMULA

G.f.: x*(7*x^8+6*x^7+x^6+2*x^5+18*x^4+13*x^3+6*x^2+3*x+4) / ((1-x)^2*(1+x)*(1+x^2)*(1+x^4)). - Colin Barker, Jun 16 2013

a(n) ~ 15*n/2. - Stefano Spezia, Jul 09 2023

MATHEMATICA