A121402 Prime values of integers written in factorial base, interpreted as in base 10.

11, 101, 211, 311, 1021, 1201, 1301, 1321, 2011, 2111, 2221, 2311, 3001, 3011, 3121, 3221, 3301, 4001, 4021, 4111, 4201, 4211, 10111, 10211, 10301, 10321, 11311, 11321, 12011, 12101, 12211, 12301, 13001, 13121, 14011, 14221, 14321, 20011, 20021, 20101, 20201, 21001

Offset

1,1

Links

Table of n, a(n) for n=1..42.

Index entries for sequences related to factorial base representation.

Example

a(1) = 11 = 1*(2!) + 1*(1!) = A007623(3)_10.
a(2) = 101 = 1*(3!) + 0*(2!) + 1*(1!) = A007623(7)_10.
a(3) = 211 = 2*(3!) + 1*(2!) + 1*(1!) = A007623(15)_10.
a(4) = 311 = 3*(3!) + 1*(2!) + 1*(1!) = A007623(21)_10.
a(5) = 1021 = 1*(4!) + 0*(3!) + 2*(2!) + 1*(1!) = A007623(29)_10.
a(6) = 1201 = 1*(4!) + 2*(3!) + 0*(2!) + 1*(1!) = A007623(37)_10.
a(7) = 1301 = 1*(4!) + 3*(3!) + 0*(2!) + 1*(1!) = A007623(43)_10.
a(8) = 1321 = 1*(4!) + 3*(3!) + 2*(2!) + 1*(1!) = A007623(47)_10.

Mathematica

f[n_] := Module[{k = n, m = 2, r, s = {}}, While[{k, r} = QuotientRemainder[k, m]; k != 0|| r != 0, AppendTo[s, r]; m++]; FromDigits[Reverse @ s]]; Select[Array[f, 300], PrimeQ] (* Amiram Eldar, Feb 21 2024 *)

Crossrefs

Cf. A007623 (Integers written in factorial base).

Sequence in context: A142317 A180406 A174884 * A156307 A057532 A193699

Adjacent sequences: A121399 A121400 A121401 * A121403 A121404 A121405

Keyword

base,easy,nonn

Author

Jonathan Vos Post, Sep 06 2006

Extensions

More terms from Amiram Eldar, Feb 21 2024

Status

approved