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A241989
Positive numbers n that are divisible by the sum of the digits of n in base 16.
2
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, 50, 54, 60, 64, 65, 66, 70, 72, 75, 80, 90, 96, 99, 100, 105, 108, 112, 120, 126, 128, 130, 132, 135, 140, 144, 150, 160, 165, 175, 176, 180, 192, 195, 198, 200
OFFSET
1,2
COMMENTS
A base 16 version of Harshad (or Niven) numbers (A005349).
Numbers n such that n = 0 modulo A053836(n). - Antti Karttunen, Aug 22 2014
EXAMPLE
82478 is in the sequence as it is 1422E in hexadecimal and 1+4+2+2+14 = 23 which divides 82478.
MATHEMATICA
Select[Range[200], Divisible[#, Total@ IntegerDigits[#, 16]] &] (* Indranil Ghosh, Jun 12 2017 *)
PROG
(Python)
from gmpy2 import digits
A241989 = [n for n in range(1, 10**3) if not n % sum([int(d, 16) for d in digits(n, 16)])]
(MIT/GNU Scheme, with Antti Karttunen's IntSeq-library)
(define A241989 (MATCHING-POS 1 1 (lambda (n) (zero? (modulo n (A053836 n))))))
(define (A053836 n) (let loop ((n n) (i 0)) (if (zero? n) i (loop (floor->exact (/ n 16)) (+ i (modulo n 16))))))
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Chai Wah Wu, Aug 22 2014
STATUS
approved