This site is supported by donations to The OEIS Foundation.

 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!)
 A173562 a(n) = n^2 + floor(n/4). 5
 0, 1, 4, 9, 17, 26, 37, 50, 66, 83, 102, 123, 147, 172, 199, 228, 260, 293, 328, 365, 405, 446, 489, 534, 582, 631, 682, 735, 791, 848, 907, 968, 1032, 1097, 1164, 1233, 1305, 1378, 1453, 1530, 1610, 1691, 1774, 1859, 1947, 2036, 2127, 2220, 2316, 2413, 2512 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 LINKS Index entries for linear recurrences with constant coefficients, signature (2,-1,0,1,-2,1). FORMULA a(n) = A002378(n)-A057353(n) = A035608(n)-A002265(n+2) = A000290(n)+A002265(n); a(n+1) - a(n) = A047624(n+2). a(n) = floor((n + 1/8)^2). a(n) = 2*a(n-1) - a(n-2) + a(n-4) - 2*a(n-5) + a(n-6) for n>5. G.f.: x*(1+2*x+2*x^2+3*x^3)/((1+x)*(x^2+1)*(1-x)^3). - R. J. Mathar, Feb 27 2010 a(n) = (8*n^2+2*n-3+i^(2*n)+(1+i)*i^(-n)+(1-i)*i^n)/8 where i=sqrt(-1). - Wesley Ivan Hurt, Jun 04 2016 MAPLE A173562:=n->floor((n + 1/8)^2): seq(A173562(n), n=0..80); # Wesley Ivan Hurt, Jun 04 2016 MATHEMATICA Table[n^2+Floor[n/4], {n, 0, 50}] (* or *) LinearRecurrence[{2, -1, 0, 1, -2, 1}, {0, 1, 4, 9, 17, 26}, 50] (* Harvey P. Dale, Nov 25 2011 *) PROG (PARI) a(n)=n^2+n\4 \\ Charles R Greathouse IV, Oct 16 2015 (MAGMA) [Floor((n + 1/8)^2) : n in [0..80]]; // Wesley Ivan Hurt, Jun 04 2016 CROSSREFS Cf. A000290, A002265, A002378, A035608, A047624, A057353. Sequence in context: A295494 A092464 A328271 * A161320 A170879 A134578 Adjacent sequences:  A173559 A173560 A173561 * A173563 A173564 A173565 KEYWORD nonn,easy AUTHOR Reinhard Zumkeller, Feb 21 2010 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 December 16 00:33 EST 2019. Contains 330013 sequences. (Running on oeis4.)