login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A055223 One-fourth the digital sum of base 5 representations of 2^n. 2

%I

%S 1,1,1,1,2,1,1,2,3,3,3,3,2,3,4,5,5,5,4,3,5,6,7,5,8,8,6,8,10,10,8,6,7,

%T 8,8,10,7,9,9,10,11,10,9,10,9,11,11,11,11,12,13,13,12,14,10,14,17,15,

%U 13,13,12,15,14,16,15,12,14,15,15,16,15,15,15,16,13,12,16,17,14,20,20,20

%N One-fourth the digital sum of base 5 representations of 2^n.

%e a(19) = 4 because 2^20 = 1048576 = 232023301 (to scale 5) and (2+3+2+0+2+3+3+0+1)/4 = 4

%t a[n_] := 1/4* Module[{aux = IntegerDigits[2^(n + 1), 5]},Sum[aux[[i]], {i, 1, Length[aux]}]] [From _José María Grau Ribas_, Feb 13 2010]

%Y Cf. A000866.

%K nonn,base

%O 2,5

%A _Lekraj Beedassy_, Jun 20 2000

%E More terms from _James A. Sellers_, Jul 04 2000

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified May 31 07:06 EDT 2020. Contains 334747 sequences. (Running on oeis4.)