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

Author

Antti Karttunen, Nov 02 2021

Keywords

• nonn

Crossrefs

Cf. A002144, A002145, A348744, A348747.

Programs

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];