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A245385 Numbers N such that N = P//Q = R//S, where // is the concatenation function, satisfying the following properties: P and S are m-digit integers, Q and R are k-digit integers, k and m are distinct positive integers, and P*Q = R*S. 1

%I #10 Jul 23 2014 10:27:21

%S 111,164,195,222,265,333,444,498,555,666,777,888,999,1111,1664,1995,

%T 2222,2665,3333,4444,4847,4998,5555,6545,6666,7424,7777,8888,9999,

%U 11111,16664,19995,21775,22222,24996,26665,33333,43243,44444,49998,55555,66666,77777,86486,88888,99999

%N Numbers N such that N = P//Q = R//S, where // is the concatenation function, satisfying the following properties: P and S are m-digit integers, Q and R are k-digit integers, k and m are distinct positive integers, and P*Q = R*S.

%e Take the number 21775.

%e 2*1775 != 2177*5.

%e 21*775 == 217*75 = 16275. Thus 21775 is a member of this sequence.

%o (Python)

%o for n in range(1,10**5):

%o ..s = str(n)

%o ..count = 0

%o ..for i in range(1,len(s)):

%o ....num = int(s[:i])*int(s[i:])

%o ....if i != len(s) - i:

%o ......if num != 0:

%o ........if num == int(s[:len(s)-i])*int(s[len(s)-i:]):

%o ..........count += 1

%o ..........break

%o ..if count > 0:

%o ....print(n,end=', ')

%Y Cf. A245364, A245386.

%K nonn,base

%O 1,1

%A _Derek Orr_, Jul 20 2014

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Last modified April 25 09:56 EDT 2024. Contains 371967 sequences. (Running on oeis4.)