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 A092481 #5 Mar 14 2015 16:24:44 %S A092481 1,3,3,8,9,20,29,60,93,189,315,618,1095,2114,3855,7414,13797,26478, %T A092481 49939,95838,182361,350572,671091,1292604,2485533,4797616,9256395, %U A092481 17903928,34636833,67125304,130150587,252677904,490853415,954502948 %N A092481 Number of different sets of n-gons labeled 1...n such that all members of each set contain equivalent paths with increasing labels; i.e., the number of isotemporal classes of n-gons. %D A092481 B. de Bivort, Isotemporal classes of n-gons, preprint, 2004. %D A092481 B. de Bivort, An introduction to temporal networks, preprint, 2004. %H A092481 B. de Bivort, <a href="http://arXiv.org/abs/math.CO/0501171">Isotemporal classes of n-gons</a> %F A092481 If n odd: (1/n) sum_{d|n} (2^(n/d-1)-1) phi(d). %F A092481 If n = 4k + 2: (1/n) {sum_{d|n} (2^(n/d-1) phi(d)) - sum_{c|n/2} (2^(n/2c-1) phi(2c)} + 2^(n-4)/2 %F A092481 If n = 4k: (1/n) {sum_{d|n} (2^(n/d-1) phi(d)) - sum_{c|n/2} (2^(n/2c-1) phi(2c))} + 2^(n-4)/2 + 2^(n-8)/4 - 2^(ceiling[(n-4)/8]-1). %t A092481 f[n_] := Block[{d = Divisors[n], c = Divisors[n/2]}, Switch[ Mod[n, 4], 0, (Plus @@ (2^(n/d - 1)EulerPhi[d]) - Plus @@ (2^(n/(2c) - 1)EulerPhi[2c]))/n + 2^((n - 4)/2) + 2^((n - 8)/4) - 2^(Ceiling[(n - 4)/8] - 1), 1, (Plus @@ ((2^(n/d - 1) - 1)EulerPhi[d]))/n, 2, (Plus @@ (2^(n/d - 1)EulerPhi[d]) - Plus @@ (2^(n/(2c) - 1)EulerPhi[2c]))/n + 2^((n - 4)/2), 3, (Plus @@ ((2^(n/d - 1) - 1)EulerPhi[d]))/n]]; Table[ f[n], {n, 3, 36}] %Y A092481 Cf. A000031, A000029, A027671. %K A092481 nonn %O A092481 3,2 %A A092481 Benjamin de Bivort (bivort(AT)fas.harvard.edu), Apr 03 2004 %E A092481 Edited by _Robert G. Wilson v_, Apr 09 2004