A178741 - OEIS

%I #5 Aug 02 2015 12:54:00

%S 2,3,5,8,13,19,26,35,46,59,73,88,105,124,145,167,190,217,246,277,309,

%T 343,379,416,457,499,542,587,633,680,729,779,830,883,937,992,1049,

%U 1107,1166,1227,1289,1352,1419,1487,1556,1627,1699,1772,1847,1923,2000,2079

%N a(1)=2. For a(n)+1, differences must be strictly increasing and consecutive terms are relatively prime

%e a(5) cannot be 12 because 8 and 12 are not relatively prime

%t f[s_] := Block[{k = 2 s[[ -1]] - s[[ -2]] + 1}, While[ GCD[k, s[[ -1]]] > 1, k++ ]; Append[s, k]]; Rest@ Nest[f, {2, 2}, 51] (* _Robert G. Wilson v_, Jun 09 2010 *)

%K nonn

%O 1,1

%A _J. Lowell_, Jun 08 2010

%E a(11) onwards from _Robert G. Wilson v_, Jun 09 2010