A209493 Indices of primes in sequence A006190.

2, 5, 11, 17, 61, 103, 167, 193, 293, 643, 647, 911, 11243, 29437, 55021, 80141

Offset

1,1

Comments

Index must be prime. The indices greater than 293 yield probable primes.

Links

Table of n, a(n) for n=1..16.

Mathematica

seq=RecurrenceTable[{a[n]==3*a[n-1]+a[n-2], a[1]==1, a[2]==3}, a, {n, 1000}]; Select[Range[1000], PrimeQ[seq[[#]]]&]

Crossrefs

Cf. A006190, A006497, A000129, A096650.

Sequence in context: A038977 A141778 A191053 * A117877 A226215 A169745

Adjacent sequences: A209490 A209491 A209492 * A209494 A209495 A209496

Keyword

nonn,hard,more

Author

Vaclav Kotesovec, Mar 09 2012

Extensions

a(14)-a(15) from Vaclav Kotesovec, Sep 08 2013

a(16) from Michael S. Branicky, Nov 03 2024

Status

approved