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!)
 A062097 a(1) = 1; a(n) = sum of the sum and the product of all previous terms. 2
 1, 2, 5, 18, 206, 37312, 1383566504, 1914204327753559888, 3664178205741957271429583378492509856, 13426201923434349344563612023870972836592501276745812341399323779519061312 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS The next term has 147 digits. [From Harvey P. Dale, Nov 01 2011] LINKS Reinhard Zumkeller, Table of n, a(n) for n = 1..13 FORMULA For n>=4, a(n) = 2*a(n-1) + a(n-2)*(a(n-1) - 2*a(n-2))*(a(n-1) -1)/(a(n-2) -1). - Leroy Quet, Nov 27 2007 EXAMPLE a(4)=18 as 18 = {1+2+5} + {1*2*5}, where 1, 2, 5 are the previous terms. MATHEMATICA lf[l_List] := Append[l, Plus @@ l + Times @@ l]; Nest[f, {1}, 9] (* Harvey P. Dale, Nov 01 2011 *) and modified by Robert G. Wilson v, Sep 03 2012 PROG (PARI) A062097(n, s=0, p=1)={for(n=2, n, p*=-s+s+=s+p); p+s} \\ - M. F. Hasler, Sep 03 2012 (Haskell) a062097 n = a062097_list !! (n-1) a062097_list = 1 : f 1 1 where    f u v = w : f (u + w) (v * w) where w = u + v -- Reinhard Zumkeller, Mar 20 2014 CROSSREFS Cf. A057194. Sequence in context: A097584 A197855 A289126 * A323706 A125765 A068873 Adjacent sequences:  A062094 A062095 A062096 * A062098 A062099 A062100 KEYWORD nonn,easy AUTHOR Amarnath Murthy, Jun 19 2001 EXTENSIONS Corrected and extended by Larry Reeves (larryr(AT)acm.org), Jun 19 2001 More terms from Harvey P. Dale, Nov 01 2011 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 June 20 12:49 EDT 2021. Contains 345164 sequences. (Running on oeis4.)