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 A113019 #17 Nov 17 2019 15:09:35 %S A113019 1,1,1,1,1,1,1,1,1,1,2,4,8,16,32,64,128,256,512,2,4,8,16,32,64,128, %T A113019 256,512,2,4,8,16,32,64,128,256,512,2,4,8,16,32,64,128,256,512,2,4,8, %U A113019 16,32,64,128,256,512,2,4,8,16,32,64,128,256,512,2,4,8,16,32 %N A113019 (Number of digits of n) raised to the power of (the digital root of n). %C A113019 n=1 and 32 are fixed points. Are there any others? %C A113019 First occurrence of k: 1,10,100,11,10000,100000,1000000,12,101,1000000000, ..., . - _Robert G. Wilson v_ %H A113019 Nathaniel Johnston, <a href="/A113019/b113019.txt">Table of n, a(n) for n = 0..10000</a> %F A113019 a(ijk...) [m digits ijk...] = m^(i+j+k+..[one digit]) %F A113019 a(n)=A055642(n)^A010888(n). - _Robert G. Wilson v_ %e A113019 a(0) = 1^0 = 1. %e A113019 a(9) = 1^9 = 1. %e A113019 a(10) = 2^(1+0) = 2. %e A113019 a(89) = 2^(8+9=17=>1+7) = 2^8 = 256. %p A113019 A113019 := proc(n) if(n=0)then return 1:fi: return length(n)^(((n-1) mod 9) + 1): end: seq(A113019(n),n=0..100); # _Nathaniel Johnston_, May 04 2011 %t A113019 f[n_] := If[n == 0, 1, Floor[ Log[10, 10n]]^(Mod[n - 1, 9] + 1)]; Table[ f[n], {n, 0, 73}] (* _Robert G. Wilson v_, Jan 04 2006 *) %o A113019 (PARI) apply( A113019(n)=(logint(n+!n,10)+1)^((n-1)%9+1), [0..99]) \\ _M. F. Hasler_, Nov 17 2019 %Y A113019 Cf. A101337. %K A113019 base,easy,nonn %O A113019 0,11 %A A113019 _Alexandre Wajnberg_, Jan 03 2006