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

1,1

Links

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

Formula

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

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

Prog

(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];

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.

Sequence in context: A126054 A387523 A067836 * A108546 A065107 A338944

Adjacent sequences: A332803 A332804 A332805 * A332807 A332808 A332809

Keyword

nonn

Author

Antti Karttunen, Feb 27 2020

Status

approved