%I #30 Aug 22 2024 05:18:21

%S 749,208,6503705,1831,657,1045880,6503711,239879,375325,7864,45075,

%T 7064,2313602,6503717,59,1766468,78975,840,1046,33355,2133,109,107390,

%U 56057,6503758,3386573,6503759,2044,3386575,158964,2313623,9463,2313625,36081

%N Highest m such that prime(m) divides the n-th pandigital (A050278).

%H Chai Wah Wu, <a href="/A071924/b071924.txt">Table of n, a(n) for n = 1..10000</a>

%e The 10th pandigital 1023457896 has prime decomposition 2^3*3^3*59*80309 and 80309 is indeed the a(10)=7864th prime, i.e., prime(7864)=80309.

%t PrimePi[FactorInteger[#][[-1,1]]]&/@(Select[Sort[FromDigits/@ Permutations[ Range[0,9]]],IntegerLength[#]>9&,50]) (* _Harvey P. Dale_, Jun 06 2018 *)

%o (Python)

%o from itertools import permutations, islice

%o from sympy import primepi, primefactors

%o def A071924(n): return primepi(max(primefactors(next(islice((int(e+''.join(d)) for e in '123456789' for d in permutations('0123456789'.replace(e,''),9)),n-1,None))))) # _Chai Wah Wu_, Dec 07 2021

%Y Cf. A050278.

%K nonn,base,fini

%O 1,1

%A _Lekraj Beedassy_, Jun 14 2002

%E a(24)-a(33) from _Donovan Johnson_, Jan 25 2009

%E Edited by _Charles R Greathouse IV_, Aug 02 2010

%E Keyword "fini" added by _Sean A. Irvine_, Aug 21 2024