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A152870
Indices of primes in the Padovan sequence A000931.
1
8, 9, 10, 12, 13, 19, 24, 35, 42, 89, 133, 474, 671, 1267, 1578, 2008, 2215, 2294, 4168, 5558, 6572, 8566, 11235, 18742, 35839, 44264, 536490, 727739
OFFSET
1,1
FORMULA
a(n) = A112882(n) + 5. - Amiram Eldar, Nov 10 2024
MATHEMATICA
a[0] = 1; a[1] = 0; a[2] = 0;
a[n_] := a[n] = a[n - 2] + a[n - 3];
Flatten[Table[If[PrimeQ[a[n]], n, {}], {n, 0, 10000}]]
PROG
(PARI) v=[1, 1, 1]; for(n=8, 1e4, v=[v[2], v[3], v[1]+v[2]]; if(ispseudoprime(v[3]), print1(n", "))) \\ Charles R Greathouse IV, Nov 07 2011
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Roger L. Bagula, Dec 14 2008
EXTENSIONS
a(23)-a(26) from Charles R Greathouse IV, Nov 07 2011
a(27)-a(28) calculated from the data at A112882 by Amiram Eldar, Nov 10 2024
STATUS
approved