(Translated by https://www.hiragana.jp/)
# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/ Search: id:a020679 Showing 1-1 of 1 %I A020679 #15 Jun 08 2014 15:33:05 %S A020679 0,3,7,10,12,19,27,28,31,34,40,48,55,63,66,75,76,82,90,103,108,111, %T A020679 112,115,124,136,138,139,147,154,160,171,175,178,187,192,199,202,210, %U A020679 220,223,243,250,252,255,259,264,271,279,283,300,304,306,307,322,327,328,343,346 %N A020679 Numbers of form 3*x^2 + 7*y^2. %H A020679 N. J. A. Sloane et al., Binary Quadratic Forms and OEIS (Index to related sequences, programs, references) %t A020679 With[{upto=350},Select[Union[3#[[1]]^2+7#[[2]]^2&/@Tuples[Range[ 0, Floor[(Sqrt[upto/3])]],2]],#<+upto&]] (* _Harvey P. Dale_, Nov 17 2012 *) %K A020679 easy,nonn %O A020679 1,2 %A A020679 _David W. Wilson_ # Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE