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A104499
Primes by index in A001945.
3
4, 6, 8, 9, 10, 11, 15, 17, 19, 23, 25, 31, 41, 47, 59, 61, 71, 113, 127, 137, 157, 167, 223, 401, 443, 457, 503, 523, 619, 701, 859, 991, 1021, 1187, 1217, 1223, 1361, 1847, 1867, 2237, 2579, 2693, 3313, 4219, 4931, 4967, 5413, 7727, 8011, 8387, 8761, 11083, 13781, 16871, 23311, 28661, 28871, 29123
OFFSET
1,1
COMMENTS
All terms greater than a(11)=25 are prime so far.
a(80) > 10^6. - Paul Vanderveen, Oct 02 2022
LINKS
FORMULA
A001945(a(n+1)) = A204138(n). [Reinhard Zumkeller, Jan 11 2012]
MATHEMATICA
a[0] = 0; a[1] = a[2] = a[3] = a[5] = 1; a[4] = 5; a[n_] := a[n] = -a[n - 1] + a[n - 2] + 3a[n - 3] + a[n - 4] - a[n - 5] - a[n - 6]; lst = {}; Do[ If[ PrimeQ[a [ n]], AppendTo[lst, n]], {n, 21900}]; lst
PROG
(Haskell)
import Data.List (findIndices)
a104499 n = a104499_list !! (n-1)
a104499_list = findIndices ((== 1) . a010051) a001945_list
-- Reinhard Zumkeller, Jan 11 2012
CROSSREFS
Cf. A001945.
Sequence in context: A299540 A085558 A084984 * A338941 A137353 A336371
KEYWORD
nonn
AUTHOR
Robert G. Wilson v, Mar 10 2005
EXTENSIONS
a(50) and a(52) corrected and more terms from Paul Vanderveen, Jul 27 2022
STATUS
approved