login

Reminder: The OEIS is hiring a new managing editor, and the application deadline is January 26.

Row sums of A092821.
1

%I #3 Mar 30 2012 18:37:44

%S 1,3,10,32,100,312,988,3208,10728,36944,130604,471880,1734616,6461808,

%T 24317080,92222288,351854032,1348762016,5189792716,20031335240,

%U 77516440696,300630949424,1168151092552,4546596321392,17721978842800

%N Row sums of A092821.

%F Superseeker suggested (1-x+ 2 I x^2/Sqrt[ -1+ 4 x])/(1-2 x)^2, first 32 terms agreeing.

%t Table[Sum[(# Conjugate[ # ]&)@ Sum[Binomial[n, t] I^t, {t, 0, k}], {k, 0, n}], {n, 0, 32}] or also CoefficientList[Series[(1-x+2I x^2/Sqrt[ -1+4x])/(1-2x)^2, {x, 0, 32}], x]

%Y Cf. A092821.

%K easy,nonn

%O 0,2

%A _Wouter Meeussen_, Mar 06 2004