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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

Table of n, a(n) for n=1..52.

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: A301754 A120761 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 April 13 11:56 EDT 2021. Contains 342936 sequences. (Running on oeis4.)