login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A162460 First differences of A161762. 1
0, 2, 2, 7, 14, 37, 90, 232, 594, 1541, 4004, 10441, 27260, 71254, 186354, 487579, 1276002, 3339821, 8742470, 22885996, 59912930, 156848617, 410626152, 1075018897, 2814412824, 7368190922, 19290113570, 50502074767, 132215989334, 346145696821, 906220783314 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
LINKS
FORMULA
a(n) = A161762(n+1) - A161762(n).
a(n) = A000217(A000045(n+1)) + A000217(A000045(n-1)-1) - A000290(A000045(n)). - R. J. Mathar, Jul 06 2009
From Colin Barker, Feb 25 2019: (Start)
G.f.: x^2*(2 - 4*x - x^2 + x^3) / ((1 + x)*(1 - 3*x + x^2)*(1 - x - x^2)).
a(n) = 3*a(n-1) + a(n-2) - 5*a(n-3) - a(n-4) + a(n-5) for n>4.
(End)
EXAMPLE
a(1) = 0 = 1 - 1.
a(2) = 2 = 3 - 1.
a(3) = 2 = 5 - 3.
a(4) = 7 = 12 - 5.
a(5) = 14 = 26 - 12.
a(6) = 37 = 63 - 26.
MAPLE
A000217 := proc(n) n*(n+1)/2 ; end:
A000045 := proc(n) combinat[fibonacci](n) ; end:
A162460 := proc(n) A161762(n+1)-A161762(n) ; end:
A161762 := proc(n) A000217(A000045(n))-A000217( A000045(n-1)-1) ; end: seq(A162460(n), n=1..80) ; # R. J. Mathar, Jul 06 2009
PROG
(PARI) concat(0, Vec(x^2*(2 - 4*x - x^2 + x^3) / ((1 + x)*(1 - 3*x + x^2)*(1 - x - x^2)) + O(x^40))) \\ Colin Barker, Feb 25 2019
CROSSREFS
Sequence in context: A344048 A228432 A298959 * A187306 A061274 A061575
KEYWORD
nonn,easy
AUTHOR
EXTENSIONS
a(21) corrected by R. J. Mathar, Jul 05 2009
STATUS
approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified April 16 03:28 EDT 2024. Contains 371696 sequences. (Running on oeis4.)