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 A178741 a(1)=2. For a(n)+1, differences must be strictly increasing and consecutive terms are relatively prime 0
 2, 3, 5, 8, 13, 19, 26, 35, 46, 59, 73, 88, 105, 124, 145, 167, 190, 217, 246, 277, 309, 343, 379, 416, 457, 499, 542, 587, 633, 680, 729, 779, 830, 883, 937, 992, 1049, 1107, 1166, 1227, 1289, 1352, 1419, 1487, 1556, 1627, 1699, 1772, 1847, 1923, 2000, 2079 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS EXAMPLE a(5) cannot be 12 because 8 and 12 are not relatively prime MATHEMATICA 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 *) CROSSREFS Sequence in context: A120761 A355513 A281967 * A308929 A308994 A326469 Adjacent sequences: A178738 A178739 A178740 * A178742 A178743 A178744 KEYWORD nonn AUTHOR J. Lowell, Jun 08 2010 EXTENSIONS a(11) onwards from Robert G. Wilson v, Jun 09 2010 STATUS approved

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Last modified December 9 17:12 EST 2022. Contains 358702 sequences. (Running on oeis4.)