login
This site is supported by donations to The OEIS Foundation.

 

Logo

Annual Appeal: Please make a donation (tax deductible in USA) to keep the OEIS running. Over 5000 articles have referenced us, often saying "we discovered this result with the help of the OEIS".

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A186649 Total number of positive integers below 10^n requiring 2 positive biquadrates in their representation as sum of biquadrates. 19
1, 5, 14, 43, 143, 460, 1467, 4613, 14629, 46341, 146545, 463344, 1465658, 4634967, 14657277, 46350371 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

A114322(n) + a(n) + A186651(n) + A186653(n) + A186655(n) + A186657(n) + A186659(n) + A186661(n) + A186663(n) + A186665(n) + A186667(n) + A186669(n) + A186671(n) + A186673(n) + A186675(n) + A186677(n) + A186680(n) + A186682(n) + A186684(n) = A002283(n)

LINKS

Table of n, a(n) for n=1..16.

Weisstein, Eric W.: MathWorld -- Waring's Problem.

MAPLE

isbiquadrate:=proc(n) type(root(n, 4), posint); end:

isA003336:=proc(n) local x, y4; if isbiquadrate(n) then false; else for x from 1 do y4:=n-x^4; if y4<x^4 then return false; elif isbiquadrate(y4) then return true; fi; od; fi; end:

a:=proc(n) local i, k; i:=0; for k from 2 to 10^n-1 do if isA003336(k) then i:=i+1; fi; od: return(i); end: for n from 1 do print(a(n)); od;

CROSSREFS

Cf. A003336

Sequence in context: A210972 A197607 A102434 * A120901 A222988 A034530

Adjacent sequences:  A186646 A186647 A186648 * A186650 A186651 A186652

KEYWORD

nonn

AUTHOR

Martin Renner, Feb 25 2011

EXTENSIONS

a(6) from Martin Renner, Feb 26 2011

a(7)-a(16) from Lars Blomberg, May 08 2011

STATUS

approved

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

License Agreements, Terms of Use, Privacy Policy .

Last modified December 4 23:10 EST 2016. Contains 278755 sequences.