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A164324
Numbers k such that k = prime(P) + pi(P), where P is product of digits of k.
2
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
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
KEYWORD
nonn,base,more,fini
AUTHOR
Farideh Firoozbakht, Aug 13 2009
STATUS
approved