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.

A088379 a(n) = (smallest prime factor of n)^4; a(1) = 1.

This page as a plain text file.
%I A088379 #13 May 16 2025 07:27:31
%S A088379 1,16,81,16,625,16,2401,16,81,16,14641,16,28561,16,81,16,83521,16,
%T A088379 130321,16,81,16,279841,16,625,16,81,16,707281,16,923521,16,81,16,625,
%U A088379 16,1874161,16,81,16,2825761,16,3418801,16,81,16,4879681,16,2401,16
%N A088379 a(n) = (smallest prime factor of n)^4; a(1) = 1.
%H A088379 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/BiquadraticNumber.html">Biquadratic Number</a>.
%H A088379 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/LeastPrimeFactor.html">Least Prime Factor</a>.
%F A088379 a(n) = A000583(A020639(n)).
%F A088379 a(n) = A088377(n)^2. - _Amiram Eldar_, May 16 2025
%t A088379 a[n_] := FactorInteger[n][[1, 1]]^4; Array[a, 100] (* _Amiram Eldar_, May 16 2025 *)
%o A088379 (PARI) a(n) = if(n == 1, 1, factor(n)[1,1]^4); \\ _Amiram Eldar_, May 16 2025
%Y A088379 Cf. A020639, A000583, A088377, A088378.
%K A088379 nonn,easy
%O A088379 1,2
%A A088379 _Reinhard Zumkeller_, Sep 28 2003