A353731 a(n) = index where prime(n) appears in A352808.

2, 6, 4, 11, 18, 19, 16, 24, 45, 52, 63, 29, 30, 78, 122, 71, 123, 148, 46, 72, 53, 162, 96, 66, 100, 161, 243, 212, 194, 186, 394, 75, 86, 110, 114, 177, 204, 111, 254, 295, 273, 274, 494, 124, 167, 386, 338, 642, 339, 410, 347, 650, 351, 762, 159, 180, 195, 250, 191, 208, 225, 270, 284, 595, 340, 689, 290, 238, 732, 730, 258, 651, 696, 624, 749, 1062, 271, 311, 300, 326, 666, 625, 1006, 634, 1007, 1050, 269, 738, 759, 970, 898, 1443, 1122, 1123, 1139, 1570, 1483

Offset

1,1

Comments

Here prime(n) means the n-th prime in 2, 3, 5, 7, ..., not the n-th term of A352808 that happens to be a prime.

Links

Michael S. Branicky, Table of n, a(n) for n = 1..10000

Formula

a(n) = k if A352808(k) = prime(n). - Michael S. Branicky, May 17 2022

Prog

(Python)
from sympy import nextprime
from itertools import count, islice
def agen(): # generator of terms
    A352808lst = [0, 1]; A352808set = {0, 1}
    mink = p = 2
    for n in count(2):
        ahalf, k = A352808lst[n//2], mink
        while k in A352808set or k&ahalf: k += 1
        A352808lst.append(k); A352808set.add(k)
        while mink in A352808set: mink += 1
        while p in A352808set: yield A352808lst.index(p); p = nextprime(p)
print(list(islice(agen(), 76))) # Michael S. Branicky, May 17 2022

Crossrefs

Cf. A352808, A353732.

Sequence in context: A371285 A090546 A242901 * A266013 A222423 A059909

Adjacent sequences: A353728 A353729 A353730 * A353732 A353733 A353734

Keyword

nonn

Author

N. J. A. Sloane, May 17 2022

Status

approved