Search: id:A007537 Results 1-1 of 1 results found. %I A007537 M5287 %S A007537 0,1,45,15913,1073579193,4611686005542975085, %T A007537 85070591730234615801280047645054636261, %U A007537 28948022309329048855892746252171976961956366698726387156269151989162886489297 %N A007537 Number of proper covers of an n-set. %D A007537 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). %D A007537 A. J. Macula, Covers of a finite set, Math. Mag., 67 (1994), 141-144. %H A007537 Eric Weisstein's World of Mathematics, Link to a section of The World of Mathematics. %p A007537 A007537 := proc(n) 1/2*sum((-1)^k*binomial(n,k)*2^(2^(n-k)),k=0..n)-2^(2^n)/ 4 end; %Y A007537 Cf. A003465. %Y A007537 Sequence in context: A134229 A163035 A101994 this_sequence A125113 A003739 A145319 %Y A007537 Adjacent sequences: A007534 A007535 A007536 this_sequence A007538 A007539 A007540 %K A007537 nonn,easy,nice %O A007537 1,3 %A A007537 N. J. A. Sloane (njas(AT)research.att.com), Simon Plouffe (simon.plouffe(AT)gmail.com) %E A007537 One more term from Emeric Deutsch (deutsch(AT)duke.poly.edu), Aug 01 2005 Search completed in 0.001 seconds