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 A186636 #18 Sep 01 2025 23:44:14
%S A186636 0,5,34,129,356,805,1590,2849,4744,7461,11210,16225,22764,31109,41566,
%T A186636 54465,70160,89029,111474,137921,168820,204645,245894,293089,346776,
%U A186636 407525,475930,552609,638204,733381,838830,955265,1083424,1224069,1377986,1545985,1728900,1927589,2142934,2375841,2627240
%N A186636 a(n) = n*(n^3+n^2+2*n+1).
%C A186636 Number of lunar divisors of the number 11111 in base n+1.
%C A186636 From _I. J. Kennedy_, May 01 2025: (Start)
%C A186636 It appears that Table 10 of the Dismal Arithmetic paper matches the number of equivalence classes, with respect to matrix similarity, of k X k integer matrices under mod b-1 arithmetic. At least that's the case when b-1 is prime and we're dealing with a field GF(p).
%C A186636 For example, there are 805 lunar divisors of 1111_6, and there are 805 equivalence classes of 4 X 4 matrices over GF(5). (End)
%H A186636 D. Applegate, M. LeBrun and N. J. A. Sloane, <a href="http://arxiv.org/abs/1107.1130">Dismal Arithmetic</a> [Note: we have now changed the name from "dismal arithmetic" to "lunar arithmetic" - the old name was too depressing]
%H A186636 <a href="/index/Rec#order_05">Index entries for linear recurrences with constant coefficients</a>, signature (5,-10,10,-5,1).
%t A186636 Table[n(n^3+n^2+2n+1),{n,0,40}] (* _Harvey P. Dale_, Nov 14 2024 *)
%K A186636 nonn,easy,changed
%O A186636 0,2
%A A186636 _N. J. A. Sloane_, Feb 24 2011