login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A140946 Triangle T(n,k) = (-2)^n*(-1)^k if k<n; T(n,n) = (-1)^(n+1)*A001045(n+1). 0
1, -2, -1, 4, -4, 3, -8, 8, -8, -5, 16, -16, 16, -16, 11, -32, 32, -32, 32, -32, -21, 64, -64, 64, -64, 64, -64, 43, -128, 128, -128, 128, -128, 128, -128, -85, 256, -256, 256, -256, 256, -256, 256, -256, 171, -512, 512, -512, 512, -512, 512, -512, 512, -512, -341, 1024, -1024, 1024, -1024, 1024 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

The sequence appears if the values b(n+1)-2*b(n) are computed from the (flattened) sequence b(.)=A140944.

Reading the triangle by rows, taking absolute values and removing duplicates we obtain A112387.

LINKS

Table of n, a(n) for n=0..59.

FORMULA

T(n,k) = A140944(n,k+1)-2*A140944(n,k), k<n.

T(n,n) = A140944(n+1,0) -2*A140944(n,n).

EXAMPLE

1;

-2,-1;

4,-4,3;

-8,8,-8,-5;

16,-16,16,-16,11;

-32,32,-32,32,-32,-21;

64,-64,64,-64,64,-64,43;

-128,128,-128,128,-128,128,-128,-85;

MATHEMATICA

(* A = A140944 *) A[0, 0] = 0; A[1, 0] = A[0, 1] = 1; A[0, k_] := A[0, k] = A[0, k-1] + 2*A[0, k-2]; A[n_, n_] = 0; A[n_, k_] := A[n, k] = A[n-1, k+1] - A[n-1, k];  T[n_, n_] := T[n, n] = A[n+1, 0] - 2*A[n, n]; T[n_, k_] := T[n, k] = A[n, k+1] - 2*A[n, k]; Table[T[n, k], {n, 0, 10}, {k, 0, n}] // Flatten (* Jean-Fran├žois Alcover, Dec 17 2014 *)

CROSSREFS

Cf. A140513, A140589.

Sequence in context: A086484 A091335 A274883 * A008741 A110316 A111975

Adjacent sequences:  A140943 A140944 A140945 * A140947 A140948 A140949

KEYWORD

sign,tabl

AUTHOR

Paul Curtz, Jul 24 2008

EXTENSIONS

Edited by R. J. Mathar, Jul 06 2011

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 August 21 06:54 EDT 2019. Contains 326162 sequences. (Running on oeis4.)