This site is supported by donations to The OEIS Foundation.

 Please make a donation to keep the OEIS running. We are now in our 55th year. In the past year we added 12000 new sequences and reached 8000 citations (which often say "discovered thanks to the OEIS"). We need to raise money to hire someone to manage submissions, which would reduce the load on our editors and speed up editing. Other ways to donate

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A254935 Fundamental positive solution y = y1(n) of the first class of the Pell equation x^2 - 2*y^2 = -A007519(n), n>=1 (primes congruent to 1 mod 8). 6
 3, 5, 7, 7, 7, 9, 9, 11, 11, 11, 13, 15, 13, 13, 17, 15, 17, 19, 15, 17, 21, 17, 17, 21, 19, 23, 19, 19, 21, 23, 25, 21, 21, 27, 23, 29, 23, 23, 23, 23 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS For the corresponding term x1(n) see A254934(n). See A254934 also for the Nagell reference. The least positive y solutions (that is the ones of the first class) for the primes +1 and -1 (mod 8) together (including prime 2) are given in A255246. LINKS FORMULA A254934(n)^2 - 2*a(n)^2 = -A007519(n) gives the smallest positive (proper) solution of this (generalized) Pell equation. EXAMPLE See A254934. n = 3: 5^2 - 2*7^2 = 25 - 98  = 73. CROSSREFS Cf. A007519, A254934, A254936, A254937, A254938, A255232. Sequence in context: A316189 A297346 A211517 * A104199 A103470 A316852 Adjacent sequences:  A254932 A254933 A254934 * A254936 A254937 A254938 KEYWORD nonn,look,easy AUTHOR Wolfdieter Lang, Feb 18 2015 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
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified December 10 15:09 EST 2019. Contains 329896 sequences. (Running on oeis4.)