This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A107464 #8 Jun 13 2015 00:51:49 %S A107464 11,51,175,527,1471,3903,9983,24831,60415,144383,339967,790527, %T A107464 1818623,4145151,9371647,21037055,46923775,104071167,229638143, %U A107464 504365055,1103101951,2403336191,5217714175,11291066367,24360517631,52412022783,112474456063,240786604031 %N A107464 Number of fuzzy subgroups of rank 3 cyclic group of order (p^n)*q*r where p, q and r are three distinct prime. %C A107464 It would be good to find a formula for a(n,m,l) or generating function for the number of chains in the lattice of subgroups ( these are the fuzzy subgroups )of the direct sum Z_(p^n) + Z_(q^m) + Z_(r^l) for given 3 distinct prime p,q and r and for integers n,m and l. %D A107464 V. Murali, Number of chains in the power set of a set with (n+2) elements, specification n^1 1^2, preprint, 2005. %D A107464 V. Murali and B. B. Makamba, Fuzzy subgroups of finite Abelian groups III, Rhodes University Preprint, 2005. %H A107464 Colin Barker, <a href="/A107464/b107464.txt">Table of n, a(n) for n = 0..1000</a> %H A107464 V. Murali, <a href="http://www.ru.ac.za/affiliates/fuzzysystems">FSRG, Rhodes University</a>. %H A107464 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (7,-18,20,-8). %F A107464 a(n) = 2^(n+1)*(n^2 + 6n + 6) - 1. %F A107464 G.f.: (16*x^2-26*x+11) / ((x-1)*(2*x-1)^3). - _Colin Barker_, Jan 15 2015 %e A107464 a(5) = (2^6)*(5^2+6*5+6)-1= 3903. This is the number of chains in the lattice of subgroups of the direct sum Z_(p^6)+ Z_q + Z_r for 3 distinct prime p,q and r where Z_i is the group of integers modulo i. %o A107464 (PARI) Vec((16*x^2-26*x+11)/((x-1)*(2*x-1)^3) + O(x^100)) \\ _Colin Barker_, Jan 15 2015 %Y A107464 Cf. A007047, A107392. %K A107464 easy,nonn %O A107464 0,1 %A A107464 Venkat Murali (v.murali(AT)ru.ac.za), May 27 2005 %E A107464 Missing a(8) inserted by _Colin Barker_, Jan 15 2015