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.

A109600 Numbers n such that number of 1's in binary representation of n equals the number of digits required to write the prime factors of n.

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%I A109600 #10 Jul 04 2023 14:48:01
%S A109600 2,6,9,10,17,22,26,28,38,42,50,54,60,69,70,74,78,82,90,92,98,99,102,
%T A109600 114,116,131,133,134,135,137,145,146,150,153,154,161,165,169,170,172,
%U A109600 193,194,195,202,209,210,212,220,225,226,234,242,248,259,265,275,278,282
%N A109600 Numbers n such that number of 1's in binary representation of n equals the number of digits required to write the prime factors of n.
%C A109600 708588 has 13 1's in base 2 and 13 digits in its factorization. What is the next term in this sequence with more 1's and digits?
%C A109600 2881008 has 14 1's in base 2 and 14 digits in its factorization. - _Harvey P. Dale_, Jul 04 2023
%H A109600 Harvey P. Dale, <a href="/A109600/b109600.txt">Table of n, a(n) for n = 1..1000</a>
%e A109600 54=110110 in base 2 and 54=2*3*3*3, hence 54 is in the sequence.
%t A109600 Select[Range[2,300],DigitCount[#,2,1]==Total[IntegerLength[#[[1]]]#[[2]]&/@ FactorInteger[ #]]&] (* _Harvey P. Dale_, Jul 04 2023 *)
%Y A109600 Cf. A076649.
%K A109600 base,easy,nonn
%O A109600 1,1
%A A109600 _Jason Earls_, Jul 30 2005