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 A056321 #6 Aug 22 2017 20:53:08 %S A056321 0,0,0,0,60,900,8400,63000,417120,2551500,14804700,82764000,450518460, %T A056321 2404502100,12646078140,65771433000,339165516120,1737485731740, %U A056321 8855359634100,44952365429940,227475768899460 %N A056321 Number of primitive (aperiodic) reversible strings with n beads using exactly five different colors. %C A056321 A string and its reverse are considered to be equivalent. %D A056321 M. R. Nester (1999). Mathematical investigations of some plant interaction designs. PhD Thesis. University of Queensland, Brisbane, Australia. [See A056391 for pdf file of Chap. 2] %F A056321 Sum mu(d)*A056312(n/d) where d|n. %Y A056321 Cf. A056316. %K A056321 nonn %O A056321 1,5 %A A056321 _Marks R. Nester_