Search: id:A089001 Results 1-1 of 1 results found. %I A089001 %S A089001 1,3,6,9,21,24,27,30,33,36,42,45,66,72,75,87,93,96,99,102,105,123,132, %T A089001 135,153,156,162,177,186,189,201,204,219,228,237,240,255,264,273,285, %U A089001 297,300,306,321,324,327,351,357,360,366,375,387,393,399,405,417,423 %N A089001 Numbers n such that 2*n^2 + 1 is prime. %C A089001 All terms except the first one are multiples of 3. - Zak Seidov (zakseidov(AT)yahoo.com) %F A089001 a(n)=((A090698(n)-1)/2)^(1/2). %F A089001 Starting with n=2, a(n)=3*A089008(n-1). - Zak Seidov (zakseidov(AT)yahoo.com) %Y A089001 Cf. A089008, A090612, A090698. %Y A089001 Sequence in context: A018186 A015938 A116614 this_sequence A050889 A026095 A061929 %Y A089001 Adjacent sequences: A088998 A088999 A089000 this_sequence A089002 A089003 A089004 %K A089001 nonn %O A089001 1,2 %A A089001 N. J. A. Sloane (njas(AT)research.att.com), Dec 20 2003 Search completed in 0.001 seconds