A317964 - OEIS

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A317964

Prime numbers in the lexicographically earliest sequence of positive integers whose prime indices are not already in the sequence (A304360).

2, 5, 13, 17, 23, 31, 37, 43, 47, 61, 67, 73, 79, 89, 103, 107, 109, 113, 137, 149, 151, 163, 167, 179, 181, 193, 197, 223, 227, 233, 241, 251, 257, 263, 269, 271, 277, 281, 307, 317, 347, 349, 353, 359, 379, 383, 389, 397, 419, 421, 431, 433, 449, 457, 463, 467, 487, 499, 503, 509, 521, 523, 547

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OFFSET

1,1

COMMENTS

Also primes whose prime index is not in A304360, or is in A324696. A prime index of n is a number m such that prime(m) divides n. - Gus Wiseman, Mar 19 2019

LINKS

Robert Israel, Table of n, a(n) for n = 1..10000

MAPLE

count:= 0:

P:= {}: A:= NULL:

for n from 2 while count < 100 do

pn:= numtheory:-factorset(n);

if pn intersect P = {} then

P:= P union {ithprime(n)};

if isprime(n) then A:= A, n; count:= count+1 fi;

od:

A; # Robert Israel, Aug 26 2018