%I A055507
%S A055507 1,4,8,14,20,28,37,44,58,64,80,86,108,108,136,134,169,160,198,192,236,
%T A055507 216,276,246,310,288,348,310,400,344,433,396,474,408,544,450,564,512,
%U A055507 614,522,688,560,716,638,756,636,860,676,859,772,926,758,1016,804,1032
%N A055507 Sum{k = 1 to n}[d(k)*d(n+1-k)], where d(k) is number of positive divisors 
               of k.
%C A055507 a(n) = number of ways to express n+1 as a*b+c*d in positive integers 
               a, b, c, d. - David W. Wilson (davidwwilson(AT)comcast.net), Jun 
               16 2003
%C A055507 tau(n) (A000005) convolved with itself, treating this result as a sequence 
               whose offset is 2 - Graeme McRae (g_m(AT)mcraefamily.com), Jun 06 
               2006
%H A055507 Leroy Quet, <a href="http://www.prism-of-spirals.net/">Home Page</a> 
               (listed in lieu of email address)
%F A055507 G.f.: Sum_{i >= 1, j >= 1} x^(i+j-1)/(1-x^i)/(1-x^j). - Vladeta Jovovic 
               (vladeta(AT)eunet.rs), Nov 11 2001
%e A055507 a[4] = d(1)*d(4) +d(2)*d(3) +d(3)*d(2) +d(4)*d(1) = 1*3 +2*2 +2*2 +3*1 
               = 14
%Y A055507 Cf. A000385.
%Y A055507 Sequence in context: A067699 A066941 A049420 this_sequence A121896 A131937 
               A088804
%Y A055507 Adjacent sequences: A055504 A055505 A055506 this_sequence A055508 A055509 
               A055510
%K A055507 easy,nonn
%O A055507 1,2
%A A055507 Leroy Quet Jun 29 2000
%E A055507 More terms from James A. Sellers (sellersj(AT)math.psu.edu), Jul 04 2000