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A261532 Hall's sequence g_n. 0
7, 589, 11064985, 7835767761026353, 7859104819806710982081319640824417, 15811975313589523224392147529414564125936123169432771986649715567359169 (list; graph; refs; listen; history; text; internal format)
OFFSET
3,1
LINKS
James S. Hall, A remark on the primeness of Mersenne numbers, J. London Math. Soc. 28, (1953), 285-287.
FORMULA
a(n) = g(n) where g(3) = 7 and g(n+1) = 2*(g(n)-1)*(1+2^n*(g(n)-1)) + 1.
PROG
(PARI) N=11; g=vector(N); g[3] = 7;
for (n=3, N-1, g[n+1] = 2*(g[n]-1)*(1+2^n*(g[n]-1))+1 );
vector(N-3, j, g[j+2])
(Magma) [n le 1 select 7 else 2*(Self(n-1)-1)*(1+2^(n+1)*(Self(n-1)-1)) + 1: n in [1..6]]; // Vincenzo Librandi, Aug 24 2015
CROSSREFS
Sequence in context: A153405 A322899 A203680 * A295814 A087772 A047942
KEYWORD
nonn
AUTHOR
Joerg Arndt, Aug 24 2015
STATUS
approved

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Last modified July 13 12:36 EDT 2024. Contains 374284 sequences. (Running on oeis4.)