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%I #8 Feb 27 2016 09:52:58
%S 28,78,248,684,1862,3294,6140,9144,16590,27872,37734,59094,75812,
%T 90864,121878,171780,219542,257244,328104,378362,432240,530964,627570,
%U 785078,969714,1071512,1157004,1271270,1366974,1649024,2145924
%N a(n) = A000203(A251720(n))
%C Let p=prime(n)=A000040(n) and q=prime(n+1)=A000040(n+1) then a(n)=sigma(p^2*q)=1+p+q+p^2+ p*q+p^2*q.
%t p=1; Table[p=NextPrime[p];q=NextPrime[p];1+p+q+p^2+p*q+p^2*q,{20}]
%o (PARI) p=1;for(n=1,20,p=nextprime(p+1);q=nextprime(p+1);print1(sigma(p^2*q)","))
%Y Cf. A000040, A000203, A251720.
%K nonn
%O 1,1
%A _Zak Seidov_, Feb 12 2016