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%I #7 Apr 30 2023 23:16:16
%S 65,95,341,95,161,115,629,203,145,203,365,155,185,155,301,185,329,235,
%T 1541,287,185,287,413,205,329,215,469,215,905,371,365,305,553,371,
%U 1037,235,1145,623,445,371,35249,295,1133,371,497,515,749,413,305,671,565
%N Least composite k such that phi(k+12n) = phi(k)+12n and sigma(k+12n) = sigma(k) + 12n where phi is the Euler totient function and sigma is the sum of divisors function.
%C No such simultaneous solutions were found if d=12n+6.
%F a(n) = Min{k: phi(k+12n) = phi(k)+12n and sigma(k+12n) = sigma(k)+12n and k is composite} with phi(k) = A000010(k) and sigma(k) = A000203(k).
%e a(97)=10217 because 10217 is composite, phi(10217)+1164 = 9600+1164 = 10764 = phi(11381) and sigma(10217)+1164 = 10836+1164 = 12000 = sigma(11381) with 1164 = 12*97 and there is no smaller composite with these properties.
%Y A000010, A000203, A054904, A054905, A055458.
%K nonn
%O 1,1
%A _Labos Elemer_, Aug 01 2001
%E Name corrected by _Sean A. Irvine_, Apr 30 2023
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