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A114990 a(1)=a(2)=1. a(n) = a(n-2) + A000265(a(n-1)). +0
1
1, 1, 2, 2, 3, 5, 8, 6, 11, 17, 28, 24, 31, 55, 86, 98, 135, 233, 368, 256, 369, 625, 994, 1122, 1555, 2677, 4232, 3206, 5835, 9041, 14876, 12760, 16471, 29231, 45702, 52082, 71743, 123825, 195568, 136048, 204071, 340119, 544190, 612214, 850297, 1462511 (list; graph; listen)
OFFSET

1,3

COMMENT

The sequence is clearly not monotonic, however the subsequences of even terms and of odd terms are each strictly increasing. The sequence is obviously bounded above by the fibonacci sequence. The subsequence of n-th terms, where n is congruent to 2 or 3 mod 4, is bounded below by the fibonacci sequence; therefore a(2n)>f(n) for n>1. - Joseph Pedersen (jmp456(AT)psu.edu), Feb 27 2006

FORMULA

a(1)=a(2)=1; a(n)=a(n-2)+A000265(a(n-1)) - Joseph Pedersen (jmp456(AT)psu.edu), Feb 27 2006

EXAMPLE

The highest odd integer dividing a(11)=28 is 7. So a(12) = a(10) + 7 = 17 + 7 = 24.

The greatest odd divisor of a(11)=28 is 7, so a(12)= a(10)+7 = 17+7 = 24.

CROSSREFS

Cf. A000265.

Sequence in context: A062724 A126024 A127678 this_sequence A111181 A076777 A111123

Adjacent sequences: A114987 A114988 A114989 this_sequence A114991 A114992 A114993

KEYWORD

easy,nonn

AUTHOR

Leroy Quet (qq-quet(AT)mindspring.com), Feb 22 2006

EXTENSIONS

More terms from Joseph Pedersen (jmp456(AT)psu.edu) and Amy Postell (arp179(AT)psu.edu), Feb 27 2006

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Last modified November 18 20:14 EST 2008. Contains 147244 sequences.


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