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.

A025618 Numbers of form 4^i*6^j, with i, j >= 0.

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%I A025618 #28 Jul 06 2025 10:01:30
%S A025618 1,4,6,16,24,36,64,96,144,216,256,384,576,864,1024,1296,1536,2304,
%T A025618 3456,4096,5184,6144,7776,9216,13824,16384,20736,24576,31104,36864,
%U A025618 46656,55296,65536,82944,98304,124416,147456,186624,221184,262144,279936
%N A025618 Numbers of form 4^i*6^j, with i, j >= 0.
%H A025618 Amiram Eldar, <a href="/A025618/b025618.txt">Table of n, a(n) for n = 1..10000</a>
%F A025618 Sum_{n>=1} 1/a(n) = (4*6)/((4-1)*(6-1)) = 8/5. - _Amiram Eldar_, Sep 24 2020
%F A025618 a(n) ~ exp(sqrt(2*log(4)*log(6)*n)) / sqrt(24). - _Vaclav Kotesovec_, Sep 24 2020
%F A025618 a(n) = 4^A025647(n) * 6^A025658(n). - _R. J. Mathar_, Jul 06 2025
%t A025618 f[upto_]:=Module[{max4=Floor[Log[upto]/Log[4]],max6 = Floor[ Log[ upto]/ Log[6]], seq},seq=Union[4^First[#] 6^Last[#]&/@Tuples[ {Range[ 0,max4],Range[ 0,max6]}]];Select[seq,#<=upto&]];f[300000]  (* _Harvey P. Dale_, Mar 05 2011 *)
%Y A025618 Subsequence of A003586.
%K A025618 easy,nonn
%O A025618 1,2
%A A025618 _David W. Wilson_