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!)
A207260 Triangle T(n,k) with T(n,k) = k^2 + (1-(-1)^(n-k))/2. 0
0, 1, 1, 0, 2, 4, 1, 1, 5, 9, 0, 2, 4, 10, 16, 1, 1, 5, 9, 17, 25, 0, 2, 4, 10, 16, 26, 36, 1, 1, 5, 9, 17, 25, 37, 49, 0, 2, 4, 10, 16, 26, 36, 50, 64, 1, 1, 5, 9, 17, 25, 37, 49, 65, 81, 0, 2, 4, 10, 16, 26, 36 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

0,5

COMMENTS

Row sums are A171218(n).

LINKS

Table of n, a(n) for n=0..61.

FORMULA

T(n+k, n) = A002522(n) if k is odd.

T(n+k, n) = n^2 = A000290(n) if k is even.

T(2*n, n) = A137928(n), n>0.

T(2*n+1, n+1) = A080335(n).

T(n,0) = A000035(n).

T(n+1,1) = A000034(n).

T(n+2,2) = A010710(n).

T(n+3,3) = A010735(n).

Sum_{k, 0<=k<=n} T(n,k)*x^k = (-1)^n*A007590(n), A000035(n), A171218(n)

for x = -1, 0, 1 respectively.

EXAMPLE

Triangle begins :

0

1, 1

0, 2, 4

1, 1, 5, 9

0, 2, 4, 10, 16

1, 1, 5, 9, 17, 25

0, 2, 4, 10, 16, 26, 36

1, 1, 5, 9, 17, 25, 37, 49

0, 2, 4, 10, 16, 26, 36, 50, 64

1, 1, 5, 9, 17, 25, 37, 49, 65, 81

CROSSREFS

Cf. A000290, A002522, A171218, A137928, A080335

Sequence in context: A065626 A201758 A096110 * A187913 A329458 A332010

Adjacent sequences:  A207257 A207258 A207259 * A207261 A207262 A207263

KEYWORD

easy,nonn,tabl

AUTHOR

Philippe Deléham, Feb 16 2012

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 January 26 23:54 EST 2022. Contains 350601 sequences. (Running on oeis4.)