A155547 a(n) = prime(n) without prime digits in n.

2, 7, 13, 19, 23, 29, 31, 43, 53, 61, 67, 173, 179, 193, 199, 223, 227, 281, 283, 311, 317, 337, 347, 409, 419, 433, 443, 457, 461, 463, 467, 491, 503, 521, 523, 541, 547, 569, 577, 593, 599, 601, 607, 619, 641, 647, 653, 809, 811, 827, 839, 857, 859, 941, 947

Offset: 1

Author

Juri-Stepan Gerasimov, Jan 24 2009

Keywords

• nonn
• base

Comments

Prime digit = 2, 3, 5 or 7.

Links

• Harvey P. Dale, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A000027, A000040.

Programs

Maple

isA084984 := proc(n) local dgs ; dgs := convert(convert(n,base,10),set) ; if dgs intersect {2,3,5,7} <> {} then false; else true; fi; end: A084984 := proc(n) option remember ; local a ; if n = 1 then 1; else for a from procname(n-1)+1 do if isA084984(a) then RETURN(a) ; fi; od; fi; end: A155547 := proc(n) ithprime(A084984(n)) ; end: for n from 1 to 80 do printf("%d,",A155547(n)) ; od: # R. J. Mathar, Jan 25 2009

Mathematica

Prime[#]&/@Select[Range[200],NoneTrue[IntegerDigits[#],PrimeQ]&] (* Harvey P. Dale, Jan 28 2024 *)

Formula

a(n) = A000040(A084984(n)). - R. J. Mathar, Jan 25 2009