A068894 a(1) = 1; a(n) is the smallest n-th power which is congruent to 1 mod a(n-1).
1, 4, 125, 10556001, 131068195168072318688258971724480032
Offset: 1
Keywords
Examples
a(3) = 125 = 5^3 = 31*a(2) + 1 where a(2) = 4=2^2 = 3*1 + 1.
Programs
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PARI
v=vector(15):v[2]=4:print1("1,4,"):for(n=3,15, for(k=2,10^8,if(((k^n)%(v[n-1]))==1,print1(k^n","):v[n]=k^n:break)))
Extensions
Corrected and extended by Ralf Stephan, Mar 21 2003