cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A303492 Numbers m such that m divides A302205(m).

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%I A303492 #17 Sep 25 2023 14:59:50
%S A303492 1,2,3,4,6,8,9,10,12,16,18,20,24,27,30,32,36,40,48,60,64,72,80,90,96,
%T A303492 100,112,120,128,130,144,160,180,184,190,192,200,224,240,249,256,260,
%U A303492 270,279,288,300,306,320,360,384,400,401,408,412,480,512,520,528,558,576,600,612,640
%N A303492 Numbers m such that m divides A302205(m).
%e A303492 With k = 18, b = 10010, and x = concat(16,0,0,2,0) = 160020, we find that 160020 / 18 = 8890, so 18 is in this sequence.
%o A303492 (Python)
%o A303492 k = 1000
%o A303492 seq = []
%o A303492 for i in range(1,k+1):
%o A303492   b = bin(i)[2:]
%o A303492   c = len(b)
%o A303492   x = ""
%o A303492   for j in range(c):
%o A303492     x += str(int(pow(2,c-j-1)) * int(b[j]))
%o A303492   y = float(int(x))/float(i)
%o A303492   if y.is_integer():
%o A303492     seq.append(i)
%o A303492 print(seq)
%o A303492 (PARI) isok(n) = {my(b = binary(n)); s = ""; forstep (k=#b, 1, -1, s = concat(s, Str(b[#b-k+1]*2^(k-1)))); eval(s) % n == 0;} \\ _Michel Marcus_, Apr 26 2018
%Y A303492 Cf. A302205.
%K A303492 nonn,base
%O A303492 1,2
%A A303492 _J. Stauduhar_, Apr 24 2018
%E A303492 Edited by _N. J. A. Sloane_, Apr 26 2018