A309006 Product minus sum of the two previous terms in the sequence, with a(1) = 2 and a(2) = 5.
2, 5, 3, 7, 11, 59, 579, 33523, 19375715, 649512684707, 12584772018235630083, 8173969059977170083865314925891, 102867537103924486790122812065087346778963284622979
Offset: 1
Keywords
Examples
a(3) = a(1) * a(2) - (a(1) + a(2)) = 2 * 5 - (2 + 5) = 3.
Links
- Christopher C. Capobianco, Table of n, a(n) for n = 1..18
Programs
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Magma
I:=[2,5]; [n le 2 select I[n] else Self(n-1)*Self(n-2)-(Self(n-1)+Self(n-2)): n in [1..14]]; // Vincenzo Librandi, Jul 10 2019
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Mathematica
RecurrenceTable[{x[n+1]==x[n]*x[n-1]-(x[n]+x[n-1]),x[1]==2,x[2]==5},x,{n,1,18}]
Formula
a(n) = a(n-1)*a(n-2) - (a(n-1)+a(n-2)), with a(1) = 2, a(2) = 5.