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A115078 Numbers k such that k = prime(1 + d_1)*prime(1 + d_2)*...*prime(1 + d_m), where d_1 d_2 ... d_m is the decimal expansion of k. 1
171, 290, 2145, 3381, 74613, 10664845620, 14771330561681694, 2744819721528289762500 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
a(9), if it exists, must have more than 32 digits.
a(9) > 10^37 if it exists. - Chai Wah Wu, Aug 12 2017
LINKS
EXAMPLE
290 is a term because 290 = p(1+2)*p(1+9)*p(1+0) = 5*29*2.
MATHEMATICA
t={}; Do[If[n==Times@@Prime[1+IntegerDigits@n], Print[n]; AppendTo[t, n]], {n, 10^5}]; t
PROG
(PARI) is(n) = my(d=digits(n)); n==prod(i=1, #d, prime(1+d[i])) \\ Felix Fröhlich, Aug 12 2017
CROSSREFS
Cf. A097227.
Fixed points of A359802.
Sequence in context: A031900 A349097 A120819 * A183996 A062907 A266315
KEYWORD
base,nonn,more
AUTHOR
Giovanni Resta, Jan 12 2006
STATUS
approved

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Last modified May 18 15:15 EDT 2024. Contains 372662 sequences. (Running on oeis4.)