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

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A139598 A035008(n) followed by A139098(n+1). 8
 0, 8, 16, 32, 48, 72, 96, 128, 160, 200, 240, 288, 336, 392, 448, 512, 576, 648, 720, 800, 880, 968, 1056, 1152, 1248, 1352, 1456, 1568, 1680, 1800, 1920, 2048, 2176, 2312, 2448, 2592, 2736, 2888, 3040, 3200, 3360, 3528, 3696, 3872 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS Sequence found by reading the line from 0, in the direction 0, 8,... and the line from 16, in the direction 16, 48,..., in the square spiral whose vertices are the triangular numbers A000217. LINKS Index entries for linear recurrences with constant coefficients, signature (2,0,-2,1). FORMULA Array read by rows: row n gives 8*n^2 + 8n, 8*(n+1)^2. a(n) = (1-(-1)^n+4*n+2*n^2). a(n) = 2*a(n-1)-2*a(n-3)+a(n-4). G.f.: 8*x/((1-x)^3*(1+x)). [Colin Barker, Jul 22 2012] a(n) = 8*A002620(n+1). - R. J. Mathar, May 04 2014 EXAMPLE Array begins: 0, 8 16, 32 48, 72 96, 128 MATHEMATICA LinearRecurrence[{2, 0, -2, 1}, {0, 8, 16, 32}, 50] (* Harvey P. Dale, Sep 27 2019 *) CROSSREFS Cf. A000217, A035008, A046092, A139098, A077221, A139591, A139592, A139593, A139595, A139596, A139597. Sequence in context: A259751 A106841 A260711 * A137243 A303026 A068935 Adjacent sequences:  A139595 A139596 A139597 * A139599 A139600 A139601 KEYWORD easy,nonn AUTHOR Omar E. Pol, May 03 2008 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.

Last modified January 26 20:11 EST 2020. Contains 331288 sequences. (Running on oeis4.)