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A129281 a(1)=1; for n>1, a(n) = a(n-1) + (the largest value of GCD(a(k),n) for 1<=k<=n-1). 9
1, 2, 3, 5, 10, 13, 14, 16, 19, 29, 30, 36, 49, 63, 78, 94, 95, 113, 132, 142, 163, 185, 186, 198, 203, 229, 238, 252, 281, 311, 342, 358, 391, 425, 432, 468, 505, 543, 582, 592, 593, 635, 636, 680, 695, 718, 765, 813, 862, 887, 938, 990, 1043, 1097, 1152, 1180 (list; graph; refs; listen; history; internal format)
OFFSET

1,2

EXAMPLE

For those k where 1<=k<=9, GCD(a(5),10) = 10 is the largest value for a GCD(a(k),10). So a(10) = a(9) + 10 = 29.

For those k where 1<=k<=11, GCD(a(11),12) = 6 is the largest value for a GCD(a(k),12). So a(12) = a(11) + 6 = 36.

MAPLE

a[1]:=1: for n from 2 to 70 do a[n]:=a[n-1]+max(seq(gcd(a[k], n), k=1..n-1)) od: seq(a[n], n=1..70); - Emeric Deutsch (deutsch(AT)duke.poly.edu), Apr 13 2007

CROSSREFS

Cf. A129282.

Sequence in context: A050051 A083571 A123090 * A022426 A005677 A162404

Adjacent sequences:  A129278 A129279 A129280 * A129282 A129283 A129284

KEYWORD

nonn

AUTHOR

Leroy Quet Apr 07 2007

EXTENSIONS

More terms from Emeric Deutsch (deutsch(AT)duke.poly.edu), Apr 13 2007

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Last modified February 14 20:10 EST 2012. Contains 205663 sequences.