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A124873
Indices of local maxima in sequence A007408.
1
5, 17, 19, 41, 43, 53, 65, 99, 109, 118, 147, 152, 155, 161, 234, 247, 271, 293, 317, 341, 480, 483, 485, 499, 505, 681, 725, 752, 811, 850, 889, 929, 1183, 1209, 1331, 1457, 1560, 1639, 1805, 1875, 1926, 2009, 2022, 2027, 2057, 2161, 2411, 2437, 2499, 2545
OFFSET
1,1
COMMENTS
Up to n=200, A007408(n) behaves roughly like 10^(1.3 n) and there are only 14 points (for n < 200) such that A007408(n) >= A007408(n+1); they are all such that A007408(n) > A007408(n+1) < A007408(n+2).
LINKS
EXAMPLE
a(1) = 5 since k=5 is the smallest index such that A007408(k) >= A007408(k+1).
MAPLE
select(n->A007408(n)>=A007408(n+1), [$1..200]);
PROG
(PARI) v=s=0; for (n=1, 2546, if (v>=v=numerator(s+=1/n^3), print1 (n-1", "))) \\ Rémy Sigrist, Jun 03 2019
CROSSREFS
Cf. A007408.
Sequence in context: A140568 A019349 A226627 * A129745 A304129 A038964
KEYWORD
hard,nonn
AUTHOR
M. F. Hasler, Nov 11 2006
EXTENSIONS
More terms from Rémy Sigrist, Jun 03 2019
STATUS
approved