A357096 Least number whose set of decimal digits coincides with the set of decimal digits of prime(n).

2, 3, 5, 7, 1, 13, 17, 19, 23, 29, 13, 37, 14, 34, 47, 35, 59, 16, 67, 17, 37, 79, 38, 89, 79, 10, 103, 107, 109, 13, 127, 13, 137, 139, 149, 15, 157, 136, 167, 137, 179, 18, 19, 139, 179, 19, 12, 23, 27, 29, 23, 239, 124, 125, 257, 236, 269, 127, 27, 128, 238, 239

Offset

1,1

Links

Table of n, a(n) for n=1..62.

Example

prime(5) = 11 and 1 have the same set of digits {1}, and 1 is the smallest such number, hence a(5) = 1.

Maple

f:= proc(p) local L, i;
  L:= sort(convert(convert(convert(p, base, 10), set), list));
  if L[1] = 0 then L[1]:= L[2]; L[2]:= 0 fi;
  add(L[-i]*10^(i-1), i=1..nops(L)) end proc:
seq(f(ithprime(i)), i=1..100); # Robert Israel, Sep 12 2022

Mathematica

a[n_] := Module[{d = Union[IntegerDigits[Prime[n]]]}, If[d[[1]] == 0, d[[1;; 2]] = d[[2;; 1;; -1]]]; FromDigits[d]]; Array[a, 100] (* Amiram Eldar, Sep 13 2022 *)

Prog

(PARI) a(n)=my(v=vecsort(digits(prime(n)), , 8), w=v); if(v[1]==0, j=#v; w=if(j>2, v[3..j], []); w=concat(Vecrev(v[1..2]), w)); fromdigits(w)
(Python)
from sympy import prime
def a(n):
    s = "".join(sorted(set(str(prime(n)))))
    return int(s) if "0" not in s else int(s[1] + "0" + s[2:])
print([a(n) for n in range(1, 63)]) # Michael S. Branicky, Sep 12 2022

Crossrefs

Cf. A179239, A179308.

Sequence in context: A197124 A032759 A142711 * A093338 A229875 A230199

Adjacent sequences: A357093 A357094 A357095 * A357098 A357099 A357100

Keyword

nonn,base

Author

Jean-Marc Rebert, Sep 12 2022

Status

approved