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A089943
Number of digits in candidates Sierpiński numbers of the first kind.
0
1, 3, 20, 617, 315653, 41373247568, 355393490465494856466, 13111705528158638560001549984013213785610, 8923364382984350190045623219438187007104891998452120469899352728663188707599765
OFFSET
0,2
LINKS
FORMULA
a(n) = ceiling(2^(n+2^n)*log_10(2)).
MATHEMATICA
a[k_] := Ceiling[2^(k+2^k) Log[2]/Log[10]];
CROSSREFS
Sequence in context: A203228 A174972 A300917 * A108699 A162134 A296408
KEYWORD
nonn,base
AUTHOR
Eric W. Weisstein, Nov 16 2003
STATUS
approved