0,2

a(n) =n^2*2^(n+1)-n*(n-1)/2 =A059937(n)-A059672(n) =A059937(n-1)+2^(n+1)*n*(n+1)/2

a(2)=31 since binary sum of 1100+1010+1001 is 12+10+9=31.

Cf. A059672, A059673, A059937.

Adjacent sequences: A059935 A059936 A059937 this_sequence A059939 A059940 A059941

Sequence in context: A043082 A070522 A087689 this_sequence A005216 A014537 A136284

nonn

Henry Bottomley (se16(AT)btinternet.com), Feb 13 2001