The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A038481 Sums of 2 distinct powers of 7. 4

%I #11 Feb 09 2018 03:22:53

%S 8,50,56,344,350,392,2402,2408,2450,2744,16808,16814,16856,17150,

%T 19208,117650,117656,117698,117992,120050,134456,823544,823550,823592,

%U 823886,825944,840350,941192,5764802,5764808,5764850,5765144,5767202

%N Sums of 2 distinct powers of 7.

%H Robert Israel, <a href="/A038481/b038481.txt">Table of n, a(n) for n = 0..10010</a>

%F G.f.: ((1-x)*(1-7*x))^(-1) * (2 - 8*x + sum_{k>=0} ((1+5*7^k)*x^(k*(k+1)/2) + (1+41*7^k)*x^(1+k*(k+1)/2))). - _Robert Israel_, Feb 09 2018

%p seq(seq(7^i+7^j,j=0..i-1),i=1..10); # _Robert Israel_, Feb 09 2018

%t Sort[Total/@Subsets[7^Range[0,10],{2}]] (* _Harvey P. Dale_, Jul 29 2015 *)

%Y Base 7 interpretation of A038444.

%K nonn,easy

%O 0,1

%A _Olivier GĂ©rard_

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified May 14 14:46 EDT 2024. Contains 372533 sequences. (Running on oeis4.)