Search: id:A066172 Results 1-1 of 1 results found. %I A066172 %S A066172 5,7,33,135,231,273,435,465,824,6375,17115,33704,86355,207315,469395, %T A066172 603585 %N A066172 Numbers n such that EulerPhi(n+1) - EulerPhi(n) = -d(n). %C A066172 These are the n at which EulerPhi(n) is decreasing at a rate equal to d(n). %e A066172 EulerPhi(6) - EulerPhi(5) = 2 - 4 = -2 = -d(5). %t A066172 Select[ Range[ 1, 10^6 ], EulerPhi[ # ] - EulerPhi[ # + 1 ] == DivisorSigma[ 0, # ] & ] %Y A066172 Sequence in context: A153414 A104815 A007911 this_sequence A018353 A081851 A006067 %Y A066172 Adjacent sequences: A066169 A066170 A066171 this_sequence A066173 A066174 A066175 %K A066172 nonn %O A066172 1,1 %A A066172 Joseph L. Pe (joseph_l_pe(AT)hotmail.com), Dec 14 2001 Search completed in 0.001 seconds