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

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A031576 Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 78. 0
 6086, 6098, 6102, 6114, 6134, 6158, 6166, 6182, 6194, 6198, 6226, 6238, 6246, 6278, 6294, 6302, 6306, 6326, 6334, 6338, 6358, 6374, 6382, 6398, 13692, 13701, 13737, 13749, 13758, 13764, 13773, 13791, 13809, 13863, 13881, 13917, 13929, 13953, 13989 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Table of n, a(n) for n=1..39. MATHEMATICA cf78Q[n_]:=Module[{s=Sqrt[n], cf, len}, cf=If[IntegerQ[s], {1}, ContinuedFraction[s][[2]]]; len = Length[ cf]; EvenQ[len]&&cf[[len/2]]==78]; Select[Range[14000], cf78Q] (* Harvey P. Dale, Jan 31 2024 *) CROSSREFS Sequence in context: A084804 A274360 A025515 * A204966 A252329 A156200 Adjacent sequences: A031573 A031574 A031575 * A031577 A031578 A031579 KEYWORD nonn AUTHOR David W. Wilson STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified April 20 16:19 EDT 2024. Contains 371844 sequences. (Running on oeis4.)