0,2

Sum of divisors of 4^n. - Paul Barry (pbarry(AT)wit.ie), Oct 13 2005

a(n) = A099393(n) + A020522(n) = A000302(n) + A024036(n). - Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Feb 07 2006

Subsequence of A000069; A132680(a(n)) = A005408(n). - Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Aug 26 2007

Index entries for sequences related to linear recurrences with constant coefficients

Eric Weisstein's World of Mathematics, Rule 220

G.f. (1+2x)/((1-x)(1-4x)) E.g.f. 2exp(4x)-exp(x)

With a leading zero, this is a(n)=(4^n-2+0^n)/2, the binomial transform of A080925. - Paul Barry (pbarry(AT)wit.ie), May 19 2003

a(n) = (-16^n/2)*B(2n, 1/4)/B(2n) where B(n, x) is the n-th Bernoulli polynomial and B(k)=B(k, 0) is the k-th Bernoulli number. a(n)=5*a(n-1)-4*a(n-2). Also a(n) = (-4^n/2)*B(2n, 1/2)/B(2n) - Benoit Cloitre (benoit7848c(AT)orange.fr), Jun 18 2004

[seq (stirling2(2*n, 2), n=1..23)]; - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Dec 06 2006

Cf. A083421.

Adjacent sequences: A083417 A083418 A083419 this_sequence A083421 A083422 A083423

Sequence in context: A153005 A056909 A002147 this_sequence A036282 A033474 A001896

easy,nonn

Paul Barry (pbarry(AT)wit.ie), Apr 29 2003