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A062894
The prime indices of sequence A067836 (that sequence is conjectured to contain only primes).
4
1, 2, 3, 4, 6, 5, 7, 8, 9, 12, 21, 10, 11, 14, 22, 16, 23, 19, 13, 15, 41, 35, 42, 27, 20, 17, 45, 39, 29, 33, 28, 54, 26, 37, 46, 61, 47, 59, 40, 31, 57, 18, 24, 58, 36, 43, 49, 64, 80, 106, 67, 60, 65, 63, 48, 94, 85, 51, 73, 122, 105, 100, 113, 138, 104, 115, 75, 32, 82
OFFSET
1,2
LINKS
EXAMPLE
a(12)=10 because a(12) in sequence A067836 is 29, which is the 10th prime number.
MATHEMATICA
Join[{1}, a = 2; f = 1; Table[f = f*a; a = NextPrime[f + 1] - f; k = 1; While[Prime[k] != a, k++]; k, {n, 2, 69}]] (* Jayanta Basu, Aug 10 2013 *)
PROG
(Python)
from sympy import primepi, nextprime
def A062894_gen(): # generator of terms
a, f = 2, 1
yield 1
while True:
yield primepi(a:=nextprime((f:=f*a)+1)-f)
A062894_list = list(islice(A062894_gen(), 30)) # Chai Wah Wu, Sep 09 2023
CROSSREFS
Cf. A067836.
Sequence in context: A275659 A244321 A364824 * A339723 A129606 A057510
KEYWORD
nonn
AUTHOR
Frank Buss (fb(AT)frank-buss.de), Feb 13 2002
EXTENSIONS
Edited by Dean Hickerson, Jun 10 2002
STATUS
approved