A305851 a(n) = (a(n-1)+a(n-2))^(n-2) with a(1)=a(2)=1.
1, 1, 2, 9, 1331, 3224179360000, 348414297354956334043085401797347258376901025074126347562215651
Offset: 1
Links
- Eric Chen, Table of n, a(n) for n = 1..9
- Eric Chen, Table of n, a(n) for n = 1..10 (an a-file)
Crossrefs
Cf. A050923.
Programs
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Mathematica
Nest[Append[#, (#[[-1]] + #[[-2]] )^(Length@ # - 2)] &, {1, 1}, 6] (* Michael De Vlieger, Jun 11 2018 *) RecurrenceTable[{a[n] == (a[n-1] + a[n-2])^(n-2), a[1] == 1, a[2] == 1}, a, {n, 1, 7}] (* Vaclav Kotesovec, Jul 23 2018 *) nxt[{n_,a_,b_}]:={n+1,b,(a+b)^(n-1)}; NestList[nxt,{1,1,1},7][[All,2]] (* Harvey P. Dale, Nov 03 2022 *) -
PARI
a(n)=if(n<3,1,(a(n-1)+a(n-2))^(n-2)) \\ Eric Chen, Jun 14 2018
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Python
#Generates and prints a list containing the terms, up to the term with the index of seq_limit seq_limit=9 seq_list=[1,1] for seq_no in range(3,seq_limit): seq_list.append((seq_list[-1]+seq_list[-2])**(seq_no-2)) print(seq_list)
Formula
a(n) ~ c^((n-2)!), where c = 3.3203520468282576446980958620234685911457954899308569085994... - Vaclav Kotesovec, Jul 23 2018
Comments