The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A093441 Beginning with 3, primes such that a(n) - 1 == 0 (mod a(n - 1) - 1) where a(n) - 1 is a squarefree number. 1
 3, 7, 31, 211, 2311, 43891, 1272811, 16546531, 976245271, 36121074991, 1119753324691, 52628406260431, 3526103219448811, 186883470630786931, 7662222295862264131, 743235562698639620611, 54256196077000692304531 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Distinct from A073918. LINKS MATHEMATICA (* first do *) Needs["NumberTheory`NumberTheoryFunctions`"] (* then *) a[1] = 3; a[n_] := a[n] = Block[{k = m = a[n - 1] - 1}, k *= 2; While[ !PrimeQ[k + 1] || !SquareFreeQ[k], k += m]; k + 1]; Table[ a[n], {n, 17}] (* Robert G. Wilson v, Apr 30 2004 *) CROSSREFS Cf. A073918, A093442. Cf. A083772. - R. J. Mathar, Sep 05 2008 Sequence in context: A289127 A289125 A083772 * A087864 A066676 A073917 Adjacent sequences:  A093438 A093439 A093440 * A093442 A093443 A093444 KEYWORD nonn AUTHOR Amarnath Murthy, Apr 01 2004 EXTENSIONS a(7) onwards from Robert G. Wilson v, Apr 30 2004 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 May 6 13:04 EDT 2021. Contains 343585 sequences. (Running on oeis4.)