%I #11 Mar 10 2019 14:52:16
%S 5,5,19,41,109,155,271,341,505,811,929,1331,1639,1805,2161,2755,3421,
%T 3659,4421,4969,5255,6161,6805,7831,9311,10099,10505,11341,11771,
%U 12655,16001,17029,18631,19181,22051,22649,24491,26405,27721,29755,31861
%N Smallest k>1 such that k(p-1)-1 is divisible by p^2, p=n-th prime.
%e a(1)=5 because 5(2-1)-1=4 is divisible by 2^2.
%o (PARI) a(n) = {my(p = prime(n), k = 2); while ((k*(p-1)-1) % p^2, k++); k;} \\ _Michel Marcus_, Sep 28 2013
%Y Cf. A039678.
%Y A306190 is an essentially identical sequence.
%K nonn
%O 1,1
%A _Felice Russo_
%E Added constraint on k to the definition, otherwise a(1)=1 - _R. J. Mathar_, Oct 10 2010