Search: id:A027870 Results 1-1 of 1 results found. %I A027870 %S A027870 0,0,0,0,0,0,0,0,0,0,1,1,1,0,0,0,0,1,0,0,1,1,1,1,0,0,1,0,0,1,1,0,0,0,0, %T A027870 0,0,0,1,0,1,1,2,3,1,1,1,1,1,0,1,0,2,3,2,2,2,1,1,2,2,3,2,2,2,1,1,0,1,3, %U A027870 3,1,0,1,1,1,0,0,2,4,2,0,2,3,1,1,0,3,5,3,3,4,2,3,4,1,1,4,5,5,6,6,7,5,5 %N A027870 Number of zeros in 2^n. %H A027870 Harry J. Smith, Table of n, a(n) for n=0,...,1000 %e A027870 2^31 = 2147483648 so a(31) = 0 and 2^42 = 4398046511104 so a(42) = 2. %t A027870 Table[ Count[ IntegerDigits[2^n], 0], {n, 0, 100} ] %o A027870 (PARI) Count(x, d)= { local(c=0, f); while (x>9, f=x-10*(x\10); if (f==d, c++); x\=10); if (x==d, c++); return(c) } { for (n=0, 1000, a=Count(2^n, 0); write("b027870.txt", n, " ", a) ) } [From Harry J. Smith (hjsmithh(AT)sbcglobal.net), Oct 27 2009] %Y A027870 Cf. 1's A065712, 2's A065710, 3's A065714, 4's A065715, 5's A065716, 6's A065717, 7's A065718, 8's A065719, 9's A065744. %Y A027870 Sequence in context: A137329 A004579 A081371 this_sequence A070077 A122587 A086195 %Y A027870 Adjacent sequences: A027867 A027868 A027869 this_sequence A027871 A027872 A027873 %K A027870 nonn,base %O A027870 0,43 %A A027870 N. J. A. Sloane (njas(AT)research.att.com). %E A027870 a(99) - a(104) from Harry J. Smith (hjsmithh(AT)sbcglobal.net), Oct 27 2009 Search completed in 0.001 seconds