A332806 Permutation of primes, inverse of A108546.

2, 3, 5, 7, 13, 11, 17, 19, 29, 23, 37, 31, 41, 43, 53, 47, 61, 59, 71, 79, 67, 89, 101, 73, 83, 97, 107, 113, 103, 109, 131, 139, 127, 151, 137, 163, 149, 173, 181, 157, 193, 167, 199, 179, 191, 223, 229, 239, 251, 197, 211, 263, 227, 271, 233, 281, 241, 293, 257, 269, 311, 277, 317, 337, 283, 307, 349, 313, 359, 331, 347, 373, 383, 353

Offset: 1

Author

Antti Karttunen, Feb 27 2020

Keywords

• nonn

Links

• Antti Karttunen, Table of n, a(n) for n = 1..19962

Crossrefs

Cf. A000040, A108547, A332805, A332808.

Differs from its inverse A108546 for the first time at n=19, where a(19) = 71, while A108546(19) = 73.

Programs

PARI

up_to = 10000;
A332806list(up_to) = { my(v=vector(2), xs=Map(), lista=List([]), p,q,u); v[2] = 3; v[1] = 5; mapput(xs,1,1); mapput(xs,2,2); mapput(xs,3,3);  for(n=4,up_to, p = v[2-(n%2)]; q = nextprime(1+p); while(q%4 != p%4, q=nextprime(1+q)); v[2-(n%2)] = q; mapput(xs,primepi(q),n)); for(i=1, oo, if(!mapisdefined(xs, i, &u), return(Vec(lista)), listput(lista, prime(u)))); };
v332806 = A332806list(up_to);
A332806(n) = v332806[n];

Formula

a(n) = A000040(A332805(n)).

a(A000720(A108547(n))) = A108547(n).