login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 56th year, we are closing in on 350,000 sequences, and we’ve crossed 9,700 citations (which often say “discovered thanks to the OEIS”).

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A121958 Quadratic n^2-n-1 functional matrix Markov of the A001053 type. 1
0, 1, 1, 6, 67, 1279, 37158, 1524757, 83898793, 5958339060, 530376075133, 57816950528557, 7574550895316100, 1174113205724524057, 212522064787034170417, 44418285653695866141210 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,4

COMMENTS

Gets large very fast.

LINKS

Robert Israel, Table of n, a(n) for n = 1..254

FORMULA

a(n) = a(n-2) + (n^2 - 3*n + 1)*a(n-1) with a(1)=0, a(2)=1, a(3)=1. - Robert Israel, Dec 18 2018

MAPLE

f:= gfun:-rectoproc({a(n) = a(n-2)+(n^2-3*n+1)*a(n-1), a(1)=0, a(2)=1}, a(n), remember):

map(f, [$1..30]); # Robert Israel, Dec 18 2018

MATHEMATICA

M[n_] := {{0, 1}, {1, n^2 - n - 1} } v[1] = {0, 1} v[n_] := v[n] = M[n].v[n - 1] a = Table[v[n][[1]], {n, 1, 30}]

CROSSREFS

Cf. A001053.

Sequence in context: A073562 A230342 A239301 * A177555 A054746 A116005

Adjacent sequences:  A121955 A121956 A121957 * A121959 A121960 A121961

KEYWORD

nonn

AUTHOR

Roger L. Bagula, Sep 02 2006

EXTENSIONS

Edited by Robert Israel, Dec 18 2018

STATUS

approved

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified November 30 16:22 EST 2021. Contains 349423 sequences. (Running on oeis4.)