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A373799
Index of n-th prime in A374965.
6
2, 5, 9, 14, 19, 22, 25, 36, 38, 43, 47, 51, 56, 65, 72, 74, 76, 97, 100, 102, 105, 107, 110, 112, 115, 122, 125, 128, 130, 238, 255, 260, 272, 284, 286, 290, 293, 296, 300, 316, 325, 331, 562, 565, 567, 575, 578, 607, 610, 612, 617, 627, 632, 649, 651, 654, 866, 875, 878
OFFSET
1,1
LINKS
N. J. A. Sloane, Table of n, a(n) for n = 1..290 (Terms 1 through 289 were obtained using Harvey P. Dale's MMA program for A373798. For a(290), see A375028.)
N. J. A. Sloane, A Nasty Surprise in a Sequence and Other OEIS Stories, Experimental Mathematics Seminar, Rutgers University, Oct 10 2024, Youtube video; Slides [Mentions this sequence]
EXAMPLE
The fifth prime in order of appearance in A374965 is A375028(5) = 751 = A374965(19), so a(5) = 19.
PROG
(Python)
from itertools import count, islice
from sympy import isprime, nextprime
def A373799_gen(): # generator of terms
a, p = 1, 3
for i in count(1):
if isprime(a):
yield i
a = p-1
else:
a = (a<<1)+1
p = nextprime(p)
A373799_list = list(islice(A373799_gen(), 20)) # Chai Wah Wu, Jul 29 2024
CROSSREFS
Cf. A373798 (first differences), A374965, A375028.
Sequence in context: A161767 A235333 A060139 * A266899 A112265 A025281
KEYWORD
nonn
AUTHOR
STATUS
approved