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

 

Logo

Please make a donation to keep the OEIS running. We are now in our 55th year. In the past year we added 12000 new sequences and reached 8000 citations (which often say "discovered thanks to the OEIS"). We need to raise money to hire someone to manage submissions, which would reduce the load on our editors and speed up editing.
Other ways to donate

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A155551 Triangle read by rows where T(m,n)=2*m*n + m + n - 9. 4
-5, -2, 3, 1, 8, 15, 4, 13, 22, 31, 7, 18, 29, 40, 51, 10, 23, 36, 49, 62, 75, 13, 28, 43, 58, 73, 88, 103, 16, 33, 50, 67, 84, 101, 118, 135, 19, 38, 57, 76, 95, 114, 133, 152, 171, 22, 43, 64, 85, 106, 127, 148, 169, 190, 211, 25, 48, 71, 94, 117, 140, 163, 186, 209 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

The numbers 2*T(m,n)+19 =(2*n+1)*(2*m+1) are not prime.

First column: A016777, second column: A016885, third column: A016993, fourth column: A017209. - Vincenzo Librandi, Nov 20 2012

LINKS

Vincenzo Librandi, Rows n = 1..100, flattened

EXAMPLE

Triangle begins:

-5;

-2, 3;

1,  8,  15;

4,  13, 22, 31;

7,  18, 29, 40, 51;

10, 23, 36, 49, 62,  75;

13, 28, 43, 58, 73,  88,  103;

16, 33, 50, 67, 84,  101, 118, 135;

19, 38, 57, 76, 95,  114, 133, 152, 171;

22, 43, 64, 85, 106, 127, 148, 169, 190, 211; etc.

MATHEMATICA

t[n_, k_]:=2 n*k + n + k - 9; Table[t[n, k], {n, 15}, {k, n}]//Flatten (* Vincenzo Librandi, Nov 20 2012 *)

PROG

(MAGMA) [2*n*k + n + k - 9: k in [1..n], n in [1..11]]; // Vincenzo Librandi, Nov 20 2012

CROSSREFS

Cf. A153143, A153144, A016777, A016885, A016993, A017209.

Sequence in context: A089261 A111716 A178566 * A259027 A214064 A098584

Adjacent sequences:  A155548 A155549 A155550 * A155552 A155553 A155554

KEYWORD

tabl,sign,easy

AUTHOR

Vincenzo Librandi, Jan 24 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 | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified December 14 01:22 EST 2019. Contains 329978 sequences. (Running on oeis4.)