A348745 Bijection from primes to {1} U primes, a left inverse of A348744.

1, 2, 3, 7, 11, 5, 13, 19, 23, 17, 31, 29, 37, 43, 47, 41, 59, 53, 67, 71, 61, 79, 83, 73, 89, 97, 103, 107, 101, 109, 127, 131, 113, 139, 137, 151, 149, 163, 167, 157, 179, 173, 191, 181, 193, 199, 211, 223, 227, 197, 229, 239, 233, 251, 241, 263, 257, 271, 269, 277, 283, 281, 307, 311, 293, 313, 331, 317, 347, 337

Offset

1,2

Links

Table of n, a(n) for n=1..70.

Prog

(PARI)
up_to = 10000;
A348745list(up_to) = { my(lista=List([]), xs=Map(), i=2, p, q, u); mapput(xs, 3, 1); for(n=2, up_to, p = prime(n); if(1==(p%4), for(k=1+n, oo, q=prime(k); if((1==(q%4))&&!mapisdefined(xs, q), break)), while(mapisdefined(xs, prime(i)), i++); q = prime(i)); mapput(xs, q, n)); listput(lista, 1); for(i=2, oo, if(!mapisdefined(xs, prime(i), &u), return(Vec(lista)), listput(lista, prime(u)))); };
v348745 = A348745list(up_to);
A348745(n) = v348745[n];

Crossrefs

Cf. A002144, A002145, A348744, A348747.

Sequence in context: A345742 A064956 A379899 * A110449 A229082 A176363

Adjacent sequences: A348742 A348743 A348744 * A348746 A348747 A348748

Keyword

nonn

Author

Antti Karttunen, Nov 02 2021

Status

approved