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!)
 A082732 a(1) = 1, a(2) = 3, a(n) = LCM of all the previous terms + 1. 21
 1, 3, 4, 13, 157, 24493, 599882557, 359859081592975693, 129498558604939936868397356895854557, 16769876680757063368089314196389622249367851612542961252860614401811693 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS The LCM is in fact the product of all previous terms. From a(5) onwards the terms alternately end in 57 and 93. LINKS FORMULA For n>=3, a(n+1) = a(n)^2 - a(n) + 1. For n>=3, a(n) = A004168(n-3) + 1. - Max Alekseyev, Aug 09 2019 1/3 = Sum_{n=3..oo} 1/a(n) = 1/4 + 1/13 + 1/157 + 1/24493 + ... or 1 = Sum_{n=3..oo} 3/a(n) = 3/4 + 3/13 + 3/157 + 3/24493 + .... If we take segment of length 1 and cut off in each step fragment of maximal length such that numerator of fraction is 3, denominators of such fractions will be successive numbers of this sequence. - Artur Jasinski, Sep 22 2008 a(n+2)=1.8806785436830780944921917650127503562630617563236301969047995953391\ 4798717695395204087358090874194124503892563356447954254847544689332763...^(2^n). -  Artur Jasinski, Sep 22 2008 MATHEMATICA a[1] = 1; a[2] = 3; a[n_] := Apply[LCM, Table[a[i], {i, 1, n - 1}]] + 1; Table[ a[n], {n, 1, 10}] c=1.8806785436830780944921917650127503562630617563236301969047995953391479871\ 7695395204087358090874194124503892563356447954254847544689332763; Table[c^(2^n), {n, 1, 6}] or a = {}; k = 4; Do[AppendTo[a, k]; k = k^2 - k + 1, {n, 1, 10}]; a (* Artur Jasinski, Sep 22 2008 *) CROSSREFS Cf. A000058, A004168, A144743, A144779, A144780, A144781, A144782, A144783, A144784, A144785, A144786, A144787, A144788. Sequence in context: A122151 A294384 A216868 * A307893 A220846 A009286 Adjacent sequences:  A082729 A082730 A082731 * A082733 A082734 A082735 KEYWORD nonn AUTHOR Amarnath Murthy, Apr 14 2003 EXTENSIONS More terms from Robert G. Wilson v, Apr 15 2003 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 August 8 11:31 EDT 2020. Contains 336298 sequences. (Running on oeis4.)