login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 


Intersection of A002479 and A003136: N = a^2 + 2b^2 = c^2 + 3d^2 for some integers a,b,c,d.
1

%I #3 Jul 14 2012 11:32:23

%S 0,1,3,4,9,12,16,19,25,27,36,43,48,49,57,64,67,73,75,76,81,97,100,108,

%T 121,129,139,144,147,163,169,171,172,192,193,196,201,211,219,225,228,

%U 241,243,256,268,283,289,291,292,300,304,307,313,324,331,337,361,363

%N Intersection of A002479 and A003136: N = a^2 + 2b^2 = c^2 + 3d^2 for some integers a,b,c,d.

%C Contains A155574 as a subsequence (obtained by restricting a,b,c,d to be nonzero). Also contains A000290 (squares) as subsequence.

%o (PARI) isA155564(n,/* use optional 2nd arg to get other analogous sequences */c=[3,2]) = { for(i=1,#c, for(b=0,sqrtint(n\c[i]), issquare(n-c[i]*b^2) & next(2)); return);1}

%o for( n=1,500, isA155564(n) & print1(n","))

%Y Cf. A001481, A002479, A003136, A002481, A020668 ff.

%K easy,nonn

%O 1,3

%A _M. F. Hasler_, Jan 25 2009

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | 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 September 24 00:05 EDT 2024. Contains 376185 sequences. (Running on oeis4.)