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 A159001 #14 May 27 2025 10:34:28 %S A159001 33,19,3,5,1209,39,4515,54,628,695,7,3008,374,5,17,46,5,119,1,193933, %T A159001 2438553,24,37,3776,54,582,1010472,1067915,2248,46,8080756,811,98, %U A159001 10089515,10538,267794,333070617,334134,561868,159,176,1,337435,3,37,4677,801,101123,13394006,1714212,377 %N A159001 First part "s" of A159000(n). %F A159001 a(n) = floor(A159000(n)/10^l), where l is such that phi(floor(A159000(n)/10^l)) * sigma(A159000(n)%10^l) = A159000(n). - _Max Alekseyev_, May 26 2025 %e A159001 A159000(1) = 3360 = phi(33)*sigma(60) so a(1) = 33. %e A159001 A159000(5) = 451584 = phi(4515)*sigma(84) so a(5) = 4515. %Y A159001 Cf. A000010, A000203, A159000. %K A159001 nonn,base %O A159001 1,1 %A A159001 _Farideh Firoozbakht_, Jun 07 2009 %E A159001 a(3), a(4), a(11) and more terms added using A159000 by _Amiram Eldar_, Mar 18 2024 %E A159001 a(34)-a(51) from _Max Alekseyev_, May 26 2025