A241989 - OEIS

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A241989

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

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

(list; graph; refs; listen; history; text; internal format)

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

LINKS

Chai Wah Wu, Table of n, a(n) for n = 1..10000

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

Cf. A005349, A053836, A245802.

Sequence in context: A246076 A246082 A060340 * A246089 A078510 A246100

Adjacent sequences: A241986 A241987 A241988 * A241990 A241991 A241992

KEYWORD

nonn,base

AUTHOR

Chai Wah Wu, Aug 22 2014

STATUS

approved

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