A322828 a(n) is the concatenation of n and pi(n).

10, 21, 32, 42, 53, 63, 74, 84, 94, 104, 115, 125, 136, 146, 156, 166, 177, 187, 198, 208, 218, 228, 239, 249, 259, 269, 279, 289, 2910, 3010, 3111, 3211, 3311, 3411, 3511, 3611, 3712, 3812, 3912, 4012, 4113, 4213, 4314, 4414, 4514, 4614, 4715, 4815, 4915, 5015, 5115

Offset: 1

Author

G. L. Honaker, Jr., Dec 26 2018

Keywords

• nonn
• base

Examples

			a(5) = 53 because if n=5 then pi(5)=3, therefore concatenation gives 53.
		

Links

• Robert Israel, Table of n, a(n) for n = 1..10000
• Chris K. Caldwell and G. L. Honaker, Jr., Prime Curios! 1027569834

Crossrefs

Cf. A000027, A000720, A045532.

Programs

Maple

a:= n-> parse(cat(n, numtheory[pi](n))):
seq(a(n), n=1..60);  # Alois P. Heinz, Dec 28 2018

PARI

a(n) = eval(concat(Str(n), Str(primepi(n)))); \\ Michel Marcus, Dec 29 2018