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A137808
a(0) = a(1) = 1. a(n) = a(n-1) + a(n - b(n)), where b(n) is smallest prime dividing n.
2
1, 1, 2, 3, 5, 6, 11, 12, 23, 34, 57, 58, 115, 116, 231, 346, 577, 578, 1155, 1156, 2311, 3466, 5777, 5778, 11555, 13866, 25421, 36976, 62397, 62398, 124795, 124796, 249591, 374386, 623977, 748772, 1372749, 1372750, 2745499, 4118248, 6863747
OFFSET
0,3
LINKS
James A. Sellers, Feb 18 2008, Table of n, a(n) for n = 0..101
MAPLE
with(numtheory): a:=proc(n) option remember: if n = 0 or n = 1 then RETURN(1) fi: a(n-1) + a(n-ifactors(n)[2][1][1]): end: for i from 0 to 100 do printf(`%d, `, a(i)) od: # James A. Sellers, Feb 18 2008
MATHEMATICA
a = {1, 1}; Do[AppendTo[a, a[[ -1]] + a[[n - FactorInteger[n][[1, 1]] + 1]]], {n, 2, 70}]; a (* Stefan Steinerberger, Feb 14 2008 *)
CROSSREFS
Sequence in context: A117086 A344551 A081026 * A275525 A091909 A171040
KEYWORD
nonn
AUTHOR
Leroy Quet, Feb 11 2008
EXTENSIONS
Corrected and extended by Stefan Steinerberger, Feb 14 2008
STATUS
approved