OFFSET
1,1
LINKS
Index entries for linear recurrences with constant coefficients, signature (1,0,0,0,1,-1).
FORMULA
a(n) = floor((12n+2)/5).
From Chai Wah Wu, Sep 11 2018: (Start)
a(n) = a(n-1) + a(n-5) - a(n-6) for n > 6.
G.f. for a keyboard with an infinite number of keys: x*(2*x^4 + 3*x^3 + 2*x^2 + 3*x + 2)/(x^6 - x^5 - x + 1). (End)
a(n) = A060106(n) + 1 for 1 <= n <= 36. - Jianing Song, Oct 14 2019
EXAMPLE
2nd, 5th, 7th, 10th, etc. keys of piano keyboard are black.
MATHEMATICA
LinearRecurrence[{1, 0, 0, 0, 1, -1}, {2, 5, 7, 10, 12, 14}, 36] (* Harvey P. Dale, Sep 15 2018 *)
CROSSREFS
KEYWORD
fini,full,nonn
AUTHOR
David W. Wilson, Mar 02 2003
STATUS
approved