OFFSET
1,13
COMMENTS
An anagram of a k-digit number is one of the k! permutations of the digits that does not begin with 0.
LINKS
Reinhard Zumkeller, Table of n, a(n) for n = 1..10000
EXAMPLE
107 has 2 prime anagrams: 107 and 701 (but not 017 or 071); so a(107) = 2.
MATHEMATICA
Table[Count[FromDigits/@Select[Permutations[IntegerDigits[n]], First[#] != 0&], _?(PrimeQ[#]&)], {n, 110}] (* Harvey P. Dale, Aug 24 2011 *)
PROG
(Haskell)
import Data.List (permutations, nub)
a046810 n = length $ filter ((== 1) . a010051)
$ map read (nub $ filter ((> '0') . head)
$ permutations $ show n)
-- Reinhard Zumkeller, Aug 14 2011
(Python)
from sympy import isprime
from itertools import permutations
def a(n): return len(set(t for p in permutations(str(n)) if p[0]!="0" and isprime(t:=int("".join(p)))))
print([a(n) for n in range(1, 106)]) # Michael S. Branicky, Feb 17 2024
CROSSREFS
KEYWORD
nonn,easy,base,nice
AUTHOR
STATUS
approved