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A322828
a(n) is the concatenation of n and pi(n).
2
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
1,1
LINKS
Chris K. Caldwell and G. L. Honaker, Jr., Prime Curios! 1027569834
EXAMPLE
a(5) = 53 because if n=5 then pi(5)=3, therefore concatenation gives 53.
MAPLE
a:= n-> parse(cat(n, numtheory[pi](n))):
seq(a(n), n=1..60); # Alois P. Heinz, Dec 28 2018
PROG
(PARI) a(n) = eval(concat(Str(n), Str(primepi(n)))); \\ Michel Marcus, Dec 29 2018
CROSSREFS
KEYWORD
nonn,base
AUTHOR
G. L. Honaker, Jr., Dec 26 2018
STATUS
approved