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A082607 a(0)=1; for n > 0, a(n) = least k not included earlier such that k*a(n-1) - 1 is a square. 3
1, 2, 5, 10, 17, 26, 37, 50, 65, 34, 13, 25, 41, 61, 85, 113, 145, 122, 101, 82, 293, 634, 1105, 53, 109, 185, 74, 149, 250, 377, 205, 146, 97, 58, 29, 73, 137, 221, 181, 650, 541, 442, 353, 274, 953, 2042, 3541, 5450, 409, 173, 370, 289, 218, 157, 106, 337, 698 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,2
LINKS
MATHEMATICA
l = {1}; Do[k = 1; While[MemberQ[l, k] || !IntegerQ[Sqrt[k*Last[l]-1]], k++ ]; AppendTo[l, k], {n, 50}]; l (* Ryan Propper, Jun 13 2006 *)
PROG
(PARI) a=[1]; print1(1", "); for(n=2, 100, k=1; f=1; while(f, if(issquare(k*a[n-1]-1), f=0; for(i=1, n-1, if(a[i]==k, f=1))); k++); a=concat(a, k-1); print1(k-1", ")) \\ Herman Jamke (hermanjamke(AT)fastmail.fm), May 01 2007
CROSSREFS
Sequence in context: A100292 A078325 A059591 * A303372 A159547 A002522
KEYWORD
nonn
AUTHOR
Amarnath Murthy, Apr 28 2003
EXTENSIONS
Corrected and extended by Ryan Propper, Jun 13 2006
Definition corrected by R. J. Mathar, Nov 12 2006
More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), May 01 2007
STATUS
approved

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Last modified March 19 07:36 EDT 2024. Contains 370957 sequences. (Running on oeis4.)