Search: id:A157949 Results 1-1 of 1 results found. %I A157949 %S A157949 127,255,383,511,639,767,895,1023,1151,1279,1407,1535,1663,1791,1919, %T A157949 2047,2175,2303,2431,2559,2687,2815,2943,3071,3199,3327,3455,3583,3711, %U A157949 3839,3967,4095,4223,4351,4479,4607,4735,4863,4991,5119,5247,5375,5503 %N A157949 a(n)=128*n-1 (n>0) %C A157949 If A=[A157948] 64*n.^2-n (63, 254, 573,.,); Y=[A010855] 16 (16, 16, 16, ,.,); X=[A157949] 128*n-1 1 (127, 255, 383.,), we have, for all terms, Pell's equation X^2-A*Y^2=1. Example: 127^2-63 *16^2=1; 255^2-254*16^2=1; 383^2-573*16^2=1. %H A157949 Edward Everett Withford, Pell Equation %H A157949 Wolfram MathWorld, Pell Equation %H A157949 Vincenzo Librandi, X^2-AY^2=1 %F A157949 a(n)=128*n-1 (n>0) %e A157949 For n=1, a(1)=127; n=2, a(2)=255; n=3, a(3)=383 %Y A157949 Cf. A157948, A010855 %Y A157949 Sequence in context: A142551 A048453 A138127 this_sequence A142165 A031933 A080035 %Y A157949 Adjacent sequences: A157946 A157947 A157948 this_sequence A157950 A157951 A157952 %K A157949 nonn %O A157949 1,1 %A A157949 Vincenzo Librandi (vincenzo.librandi(AT)tin.it), Mar 10 2009 Search completed in 0.001 seconds