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A110071
Numbers n such that n = pi(d_1!!*d_2!!*...*d_k!!) where d_1 d_2 ... d_k is the decimal expansion of n.
2
0, 4, 290, 11387, 1656281, 538311474096
OFFSET
1,2
COMMENTS
No other terms below 10^14. - Max Alekseyev, Jul 21 2024
EXAMPLE
11387 is in the sequence because 11387 = pi(1!!*1!!*3!!*8!!*7!!).
MATHEMATICA
Do[h = IntegerDigits[n]; l = Length[h]; If[n == PrimePi[ Product[h[[k]]!!, {k, l}]], Print[n]], {n, 0, 50000}]
CROSSREFS
KEYWORD
base,hard,more,nonn
AUTHOR
Farideh Firoozbakht, Jul 22 2005
EXTENSIONS
a(5) added by Farideh Firoozbakht, Dec 02 2007
a(6) from Max Alekseyev, Jul 21 2024
STATUS
approved