A354200 Prime map that sends 2 to 5, and each 4k+1 and 4k+3 prime to the next larger prime of the same type.

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

Offset: 1

Author

Antti Karttunen, May 23 2022

Keywords

• nonn

Examples

			A000040(2) = 3, and the next larger prime of the form 4k+3 is 7, therefore a(2) = 7.
A000040(3) = 5, and the next larger prime of the form 4k+1 is 13, therefore a(3) = 13.
A000040(4) = 7, and the next larger prime of the form 4k+3 is 11, therefore a(4) = 11.
		

Crossrefs

Cf. A000040, A000720, A354201, A354202.

Programs

PARI

A354200(n) = if(1==n,5,my(p=prime(n), m=p%4); forprime(q=1+p,,if(m==(q%4),return(q))));

Formula

For all n >= 1, A354201(A000720(a(n))) = A000040(n).