%I
%S 0,0,0,0,0,0,0,0,0,0,1,3,4,6,7,11,18,24,34,49,75,104,147,210,296,409,
%T 552,734,981,1311,1736,2314,3093,4139,5511,7396,9835,13106,17493,
%U 23270,31115,41664,55763,74739,100342,134559,180725,243566,327731,441270,594585,803252,1085426,1468777,1988905,2697846,3662239,4976375,6767707,9212942,12552513,17114780,23355139,31894014
%N Number of base2 strong pseudoprimes (A001262) less than 2^n.
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/StrongPseudoprime.html">Strong Pseudoprime</a>
%H Jan Feitsma and William Galway, <a href="http://www.cecm.sfu.ca/Pseudoprimes/index2to64.html">Tables of pseudoprimes and related data</a>
%e a(12)=3 since 2047, 3277 and 4033 are the 2SPSPs less than 4096.
%Y Cf. A001262, A055552, A208276
%K nonn
%O 1,12
%A _Charles R Greathouse IV_, Dec 03 2005
%E a(24)a(64) from _Charles R Greathouse IV_, Jan 28 2011, based on the calculations of Jan Feitsma.
%E a(1)=...=a(10)=0 prepended by _Max Alekseyev_, Apr 23 2013
