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

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A262104 Pseudoprimes to base 7, written in base 7. 7
 6, 34, 643, 1431, 2023, 2245, 3136, 5215, 6061, 6601, 10121, 12361, 16123, 20032, 25345, 33155, 41545, 42601, 42652, 44122, 45406, 50026, 54561, 56035, 66522, 66666, 105403, 110254, 112612, 113345, 113356, 123616, 135206, 140011, 151142, 151354, 153022, 153101, 153352, 155554 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Amiram Eldar, Table of n, a(n) for n = 1..10000 FORMULA a(n) = A007093(A005938(n)). MATHEMATICA base = 7; t = {}; n = 1; While[Length[t] < 40, n++; If[! PrimeQ[n] && PowerMod[base, n - 1, n] == 1,   AppendTo[t, FromDigits@IntegerDigits[n, 7]]]]; t FromDigits[IntegerDigits[#, 7]]&/@Select[Range[40000], CompositeQ[#] && PowerMod[ 7, #-1, #]==1&] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Feb 24 2018 *) PROG (PARI) lista(nn, b=7) = {for (n=1, nn, if (Mod(b, n)^(n-1)==1 && !ispseudoprime(n) && n>1, print1(subst(Pol(digits(n, b), x), x, 10), ", "); ); ); } \\ Michel Marcus, Sep 30 2015 CROSSREFS Cf. A005938 (pseudoprimes to base 7), A007093 (numbers in base 7). Cf. A258189, A262101, A262102, A262103, A262105, A262154. Sequence in context: A062819 A230246 A092336 * A161323 A003423 A230936 Adjacent sequences:  A262101 A262102 A262103 * A262105 A262106 A262107 KEYWORD nonn,base AUTHOR Abdul Gaffar Khan, Sep 11 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 | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified August 8 08:29 EDT 2022. Contains 356003 sequences. (Running on oeis4.)