cp's OEIS Frontend

A241989 Positive numbers n that are divisible by the sum of the digits of n in base 16.

%I A241989 #28 Jun 12 2017 10:19:23
%S A241989 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,18,20,30,32,33,35,36,40,45,48,
%T A241989 50,54,60,64,65,66,70,72,75,80,90,96,99,100,105,108,112,120,126,128,
%U A241989 130,132,135,140,144,150,160,165,175,176,180,192,195,198,200
%N A241989 Positive numbers n that are divisible by the sum of the digits of n in base 16.
%C A241989 A base 16 version of Harshad (or Niven) numbers (A005349).
%C A241989 Numbers n such that n = 0 modulo A053836(n). - _Antti Karttunen_, Aug 22 2014
%H A241989 Chai Wah Wu, <a href="/A241989/b241989.txt">Table of n, a(n) for n = 1..10000</a>
%e A241989 82478 is in the sequence as it is 1422E in hexadecimal and 1+4+2+2+14 = 23 which divides 82478.
%t A241989 Select[Range[200], Divisible[#, Total@ IntegerDigits[#, 16]] &] (* _Indranil Ghosh_, Jun 12 2017 *)
%o A241989 (Python)
%o A241989 from gmpy2 import digits
%o A241989 A241989 = [n for n in range(1,10**3) if not n % sum([int(d,16) for d in digits(n,16)])]
%o A241989 (MIT/GNU Scheme, with _Antti Karttunen_'s IntSeq-library)
%o A241989 (define A241989 (MATCHING-POS 1 1 (lambda (n) (zero? (modulo n (A053836 n))))))
%o A241989 (define (A053836 n) (let loop ((n n) (i 0)) (if (zero? n) i (loop (floor->exact (/ n 16)) (+ i (modulo n 16))))))
%Y A241989 Cf. A005349, A053836, A245802.
%K A241989 nonn,base
%O A241989 1,2
%A A241989 _Chai Wah Wu_, Aug 22 2014