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

 Please make a donation to keep the OEIS running. We are now in our 56th year. In the past year we added 10000 new sequences and reached almost 9000 citations (which often say "discovered thanks to the OEIS"). Other ways to donate

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A028400 a(n) = (2^n + 1)^2. 7
 4, 9, 25, 81, 289, 1089, 4225, 16641, 66049, 263169, 1050625, 4198401, 16785409, 67125249, 268468225, 1073807361, 4295098369, 17180131329, 68720001025, 274878955521, 1099513724929, 4398050705409, 17592194433025 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,1 LINKS H. Bottomley, Illustration of initial terms I. Strazdins, Universal affine classification of Boolean functions, Acta Applic. Math. 46 (1997), 147-167. Index entries for linear recurrences with constant coefficients, signature (7,-14,8). FORMULA a(n) = A000051(n)^2. - R. J. Mathar, Nov 27 2015 G.f.: ( -4+19*x-18*x^2 ) / ( (x-1)*(2*x-1)*(4*x-1) ). - R. J. Mathar, Nov 27 2015 PROG (PARI) a(n)=(2^n + 1)^2 CROSSREFS Sequence in context: A304167 A317975 A307396 * A237613 A220444 A117678 Adjacent sequences:  A028397 A028398 A028399 * A028401 A028402 A028403 KEYWORD nonn,easy AUTHOR 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 November 29 15:15 EST 2020. Contains 338769 sequences. (Running on oeis4.)