A110761 - OEIS

%I #29 Jan 10 2020 05:32:39

%S 1,1,2,10,16,32,72,32,112,20,96,20,144,80,80,640,288,288,48,80,80,480,

%T 384,384,512,160,768,88,64,24,128,112,20,24,128,336,80,80,640,576,112,

%U 2560,576,1792,36,192,12,48,3072,320,1792,576,2688

%N a(0) = 1; a(n+1) = tau(N) where N is the concatenation of a(0), a(1), a(2), a(3), ..., a(n).

%e a(0) = 1, a(1) = tau(1) = 1, a(2) = tau(11) = 2, a(3) = tau(112) = 10.

%p read("transforms") ;

%p A110761 := proc(n) option remember; local L ; if n = 0 then 1 ; else L := [seq(procname(i),i=0..n-1)] ; numtheory[tau]( digcatL(L)) ; end if; end proc: # _R. J. Mathar_, Apr 15 2011

%t aggluTau[0] := 1; aggluTau[n_] := aggluTau[n] = DivisorSigma[0, FromDigits[Flatten[Table[IntegerDigits[aggluTau[i]], {i, 0, n - 1}]]]]; aggluTau/@Range[0, 19] (* _Alonso del Arte_, Jan 10 2020 *)

%Y Cf. A000005 (tau).

%K nonn,base,more

%O 0,3

%A _Amarnath Murthy_, Aug 11 2005

%E a(22)-a(31) from _Carl Najafi_, Apr 15 2011

%E a(32)-a(49) from _Chai Wah Wu_, Dec 24 2019

%E a(50) from _Chai Wah Wu_, Jan 04 2020

%E a(51)-a(52) from _Chai Wah Wu_, Jan 08 2020