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.

A244438 Terms of the sequence A145749 which are not of the form 2*p where p is prime.

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%I A244438 #16 Sep 06 2014 14:53:31
%S A244438 8,188,285,902,2013,8493,37406,40977,61918,68210,90094,303853,352941,
%T A244438 360446,375565,467654,501693,724934,889285,940093,1079662,1473565,
%U A244438 1488957,1517206,1573045,1692302,1864285,2048973,2077405,2346226,2584106,2693517,3393934,3509997,3802029,4083526,4194406
%N A244438 Terms of the sequence A145749 which are not of the form 2*p where p is prime.
%H A244438 Jens Kruse Andersen, <a href="/A244438/b244438.txt">Table of n, a(n) for n = 1..702</a>
%t A244438 Select[Range[5000000], !PrimeQ[#/2] && DivisorSigma[1, #] + EulerPhi[#] == DivisorSigma[1, # + 1] + EulerPhi[# + 1] &]
%o A244438 (PARI)
%o A244438 for(n=1,10^7,s=eulerphi(n)+sigma(n);if(s==eulerphi(n+1)+sigma(n+1) && ((n%2==0 && !isprime(n/2)) || n%2),print1(n,", "))) \\ _Derek Orr_, Aug 14 2014
%Y A244438 Cf. A000010, A000203, A005384, A145749.
%K A244438 nonn
%O A244438 1,1
%A A244438 _Farideh Firoozbakht_, Aug 14 2014