A164324 Numbers k such that k = prime(P) + pi(P), where P is product of digits of k.

16, 53, 185, 238, 2495, 19775, 4878937

Offset

1,1

Comments

The product of the digits of next term (if it exists) is greater than 3*10^8.

a(8) > 10^12, if it exists. - Chai Wah Wu, Apr 24 2018

a(8) > 10^16, if it exists. - Chai Wah Wu, Apr 21 2021

Links

Table of n, a(n) for n=1..7.

Example

16 = prime(1*6) + pi(1*6), so 16 is in the sequence.
4878937 = prime(4*8*7*8*9*3*7) + pi(4*8*7*8*9*3*7), so 4878937 is in the sequence.

Mathematica

Do[If[n=Prime[m]+PrimePi[m]; m==Apply[Times, IntegerDigits[n]], Print[n]], {m, 300000000}]

Crossrefs

Cf. A000040, A000720, A007954, A164322, A164323.

Sequence in context: A332591 A117273 A137515 * A334643 A197246 A187104

Adjacent sequences: A164321 A164322 A164323 * A164325 A164326 A164327

Keyword

nonn,base,more,fini

Author

Farideh Firoozbakht, Aug 13 2009

Status

approved