1,1

Eric Weisstein's World of Mathematics, Link to a section of The World of Mathematics.

Cf. A055165, A056989.

A056990(n) = 2^(2*n-1) * A055165(n-1).

Sequence in context: A009377 A009505 A028368 this_sequence A070235 A057194 A012539

Adjacent sequences: A056987 A056988 A056989 this_sequence A056991 A056992 A056993

nonn,nice

Eric Weisstein (eric(AT)weisstein.com)

a(5) from Winston C. Yang (winston(AT)cs.wisc.edu), Aug 26 2000. Further terms computed from A055165 by David desJardins (david(AT)desjardins.org), Apr 22 2001

a(9) from Max Alekseyev, computed from A055165, Jan 15 2007