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.

A076153 Numbers n such that Omega(n) = Omega(n-1)^2, where Omega(m) (A001222) denotes the number of prime factors of m, counted with multiplicity.

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%I A076153 #16 Nov 05 2023 05:20:14
%S A076153 3,16,36,40,56,88,135,156,184,204,210,220,248,250,260,296,306,315,328,
%T A076153 330,340,342,372,414,459,472,490,516,536,546,580,584,636,650,686,690,
%U A076153 708,714,732,735,738,804,808,819,836,850,852,870,872,940,950,966,975,996,999
%N A076153 Numbers n such that Omega(n) = Omega(n-1)^2, where Omega(m) (A001222) denotes the number of prime factors of m, counted with multiplicity.
%H A076153 Amiram Eldar, <a href="/A076153/b076153.txt">Table of n, a(n) for n = 1..10000</a>
%e A076153 Omega(996) = 2^2 = Omega(995)^2, so 996 is a term of the sequence.
%t A076153 Select[Range[1000],PrimeOmega[#]==PrimeOmega[#-1]^2&] (* _Ray Chandler_, Jul 07 2015 *)
%t A076153 Flatten[Position[Partition[PrimeOmega[Range[1000]],2,1],_?(#[[1]]^2==#[[2]]&),1,Heads-> False]]+ 1 (* _Harvey P. Dale_, Nov 05 2023 *)
%Y A076153 Similar to A109287; after a(1)=3 next difference is a(101)=1792 whereas A109287(100)=1794. - _Ray Chandler_, Mar 20 2007
%Y A076153 Cf. A001222.
%K A076153 easy,nonn
%O A076153 1,1
%A A076153 _Joseph L. Pe_, Oct 31 2002
%E A076153 Edited by _Ray Chandler_, Mar 20 2007