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 A089284 #23 Mar 14 2025 18:56:53
%S A089284 2,2,4,6,8,2,8,8,48,8,16,4,8,8,8,8,72,4,64,96,16,64,128,128,8,24,256,
%T A089284 8,32,64,16,64,192,4,24,40,96,2,32,4,16,48,8,32,16,64,48,8,320,8,32,
%U A089284 48,8,64,192,48,16,32,16,64,96,128,8,120,16,64,32,48,8,32,192,512,64,96,144
%N A089284 Number of divisors of floor(Pi*10^n), Pi=3.14...
%H A089284 Tyler Busby, <a href="/A089284/b089284.txt">Table of n, a(n) for n = 0..200</a>
%H A089284 Dario Alejandro Alpern, <a href="https://www.alpertron.com.ar/ECM.HTM">Factorization using the Elliptic Curve Method</a>.
%H A089284 Hisanori Mishima, <a href="https://www.asahi-net.or.jp/~KC2H-MSM/mathland/matha1/de_pi000.htm">Decimal expansions of pi (n = 0 to 100</a>, <a href="https://www.asahi-net.or.jp/~KC2H-MSM/mathland/matha1/de_pi100.htm">n = 101 to 200</a>, <a href="https://www.asahi-net.or.jp/~KC2H-MSM/mathland/matha1/de_pi200.htm">n = 201 to 250)</a>.
%F A089284 a(n) = A000005(A011545(n)).
%e A089284 For n=4: floor(Pi*10^4)=31415 has divisors: 1,5,61,103,305,515,6283,31415; a(4)=8.
%t A089284 Table[ DivisorSigma[ 0, Floor[ Pi*10^n]], {n, 0, 10}] (* _Robert G. Wilson v_, Oct 30 2003 *)
%o A089284 (PARI) A089284(n)=numdiv(Pi\.1^n) \\ _M. F. Hasler_, Nov 01 2012
%Y A089284 Cf. A089282, A089283, A000796.
%K A089284 nonn
%O A089284 0,1
%A A089284 _Reinhard Zumkeller_, Oct 30 2003
%E A089284 More terms from _Robert G. Wilson v_ and _Ray Chandler_, Oct 30 2003