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 A063750 #29 Nov 19 2024 03:00:19
%S A063750 1,3,9,9,9,243,9,81,45,81,9,2187,27,81,729,729,9,10935,3,2187,2187,
%T A063750 1215,3,59049,243,729,567,6561,243,1594323,27,177147,729,729,2187,
%U A063750 295245,27,27,729,177147,81,7971615,81,98415,32805,729
%N A063750 Number of divisors (A000005) of the Wonderful Demlo numbers A002477.
%H A063750 Amiram Eldar, <a href="/A063750/b063750.txt">Table of n, a(n) for n = 1..352</a> (terms 1..80 from Harry J. Smith)
%F A063750 a(n) = A000005(A002477(n)) = d(((10^n-1)/9)^2). - _M. F. Hasler_, Nov 18 2017
%F A063750 a(n) = A048691(A000042(n)). - _Amiram Eldar_, Nov 19 2024
%p A063750 a:=n->((10^n-1)/9)^2: A063750:=[seq(numtheory[tau](a(n)),n=1..50)]; # _Muniru A Asiru_, Feb 17 2018
%t A063750 Array[DivisorSigma[0, FromDigits[PadRight[{}, #, 1]]^2] &, 46] (* _Michael De Vlieger_, Nov 18 2017, after _Harvey P. Dale_ at A002477 *)
%o A063750 (PARI) vector(45,n, numdiv((10^n\9)^2) ) \\ Edited by _M. F. Hasler_, Nov 18 2017
%o A063750 (PARI) apply( A063750=n->numdiv((10^n\9)^2), [1..80]) \\ _M. F. Hasler_, Nov 18 2017
%o A063750 (GAP) a:=n->((10^n-1)/9)^2;; A063750:=List([1..50],n->Tau(a(n))); # _Muniru A Asiru_, Feb 17 2018
%Y A063750 Cf. A000005, A000042, A002477, A048691.
%K A063750 nonn
%O A063750 1,2
%A A063750 _Jason Earls_, Aug 11 2001
%E A063750 Edited and offset corrected by _M. F. Hasler_, Nov 18 2017