A109710 Numbers k such that the sum of the digits of pi(k)^prime(k) is divisible by k.

1, 10, 35, 63, 106, 153, 602, 1548, 1710, 4680, 5274

Offset

1,2

Comments

Next term after 5274 is greater than 10000.

a(12) > 40000. - Jinyuan Wang, Apr 10 2020

Links

Table of n, a(n) for n=1..11.

Example

The digits of pi(1548)^prime(1548) sum to 139320 and 139320 is divisible by 1548, so 1548 is in the sequence.

Mathematica

Do[k = PrimePi[n]^Prime[n]; s = Plus @@ IntegerDigits[k]; If[Mod[s, n] == 0, Print[n]], {n, 1, 10^4}]

Prog

(PARI) is(k) = sumdigits(primepi(k)^prime(k))%k == 0; \\ Jinyuan Wang, Apr 10 2020

Crossrefs

Cf. A007953.

Sequence in context: A044468 A355491 A351860 * A000447 A052472 A331429

Adjacent sequences: A109707 A109708 A109709 * A109711 A109712 A109713

Keyword

nonn,base,hard,more

Author

Ryan Propper, Aug 08 2005

Status

approved