login
A157527
Primes using only the composite digits (4, 6, 8, 9) and all of them.
1
46489, 46889, 48649, 48869, 64489, 64849, 68449, 68489, 84649, 84869, 88469, 444869, 448969, 449689, 468499, 468869, 468889, 468899, 469849, 486449, 486869, 486949, 488689, 489689, 489869, 496849, 496889, 498469, 498689, 644489, 644869
OFFSET
1,1
COMMENTS
Subsequence of A051416.
There are no 4-digit terms so each term must have at least one repeating digit. - Harvey P. Dale, Oct 05 2023
LINKS
MAPLE
a := proc (n) if convert(convert(ithprime(n), base, 10), set) = {4, 6, 8, 9} then ithprime(n) else end if end proc: seq(a(n), n = 1 .. 53000); # Emeric Deutsch, Mar 03 2009
isA157527 := proc(n) local dgs ; if not isprime(n) then false; else dgs := convert(convert(n, base, 10), set) ; if dgs intersect {4, 6, 8, 9} <> {4, 6, 8, 9} then false; elif dgs intersect {0, 1, 2, 3, 5, 7} <> {} then false; else true; fi; fi; end: for n from 1 to 100000 do p := ithprime(n) ; if isA157527(p) then printf("%d, ", p) ; fi; od: # R. J. Mathar, Mar 03 2009
MATHEMATICA
With[{c={4, 6, 8, 9}}, Select[Flatten[Table[10 FromDigits/@Tuples[c, n]+9, {n, 5}]], PrimeQ[#] && Intersection[c, IntegerDigits[#]]==c&]] (* Harvey P. Dale, Oct 05 2023 *)
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Lekraj Beedassy, Mar 02 2009, Mar 03 2009
EXTENSIONS
Corrected and extended by numerous correspondents, Mar 04 2009
STATUS
approved