a(n)=x is the least integer such that gcd(sigma(x), sigma(x+1)) = 2*n.

Terms

a(0) =13a(1) =6a(2) =5a(3) =27a(4) =57a(5) =22a(6) =12a(7) =93a(8) =89a(9) =236a(10) =1032a(11) =14a(12) =467a(13) =83a(14) =58a(15) =308a(16) =201a(17) =118a(18) =147a(19) =56a(20) =82a(21) =1204a(22) =6301a(23) =69a(24) =596a(25) =1142a(26) =106a(27) =91a(28) =4167a(29) =87