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 A123049 #7 Mar 14 2015 18:00:18
%S A123049 0,3,33,75,2385,6345,6963,11625,18555,57825,89505,92475,265995,473625,
%T A123049 575265,1254363,1720035,3930705,4295763,4638603,5686875,6662115,
%U A123049 8731875,8782515,13964025,14951385,17714475,18979035,21868875,26854155,45546345
%N A123049 Numbers n such that (n+2) | (2^n+3^n).
%C A123049 All terms are multiples of 3. - _Robert G. Wilson v_, Sep 29 2006
%C A123049 Entries not congruent to 0 (modulo 5): 3, 33, 6963, 1254363, 4295763, 4638603, 50045553, 69151563, 114829611, 121716633, 208974987, 249618633, 292403403, ..., . - _Robert G. Wilson v_, Sep 29 2006
%t A123049 Do[m = n; If[ Mod[ PowerMod[2, n, n + 2] + PowerMod[3, n, n + 2], n + 2] == 0, Print@n], {n, 0, 45546345}] (* _Robert G. Wilson v_, Sep 29 2006 *)
%Y A123049 Cf. A045576.
%K A123049 nonn
%O A123049 1,2
%A A123049 _Zak Seidov_, Sep 25 2006
%E A123049 More terms from _Robert G. Wilson v_, Sep 29 2006