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A064801 Take 1, skip 2, take 2, skip 3, take 3, etc. 9
1, 4, 5, 9, 10, 11, 16, 17, 18, 19, 25, 26, 27, 28, 29, 36, 37, 38, 39, 40, 41, 49, 50, 51, 52, 53, 54, 55, 64, 65, 66, 67, 68, 69, 70, 71, 81, 82, 83, 84, 85, 86, 87, 88, 89, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 121, 122, 123, 124, 125, 126, 127, 128 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
A253607(a(n)) < 0. - Reinhard Zumkeller, Jan 05 2015
Integers m such that A000196(m) = A079643(m). - Firas Melaih, Dec 10 2020
Also possible values of floor(x*floor(x)) for real x >= 1. - Jianing Song, Feb 16 2021
LINKS
FORMULA
a(n) = A004202(n) - 1.
Can be interpreted as a table read by rows: T(n,k) = n^2 + k, 0 <= k < n. T(n,k) = 0 iff k > A000196(n); T(n,0) = A000290(n); T(n,1) = A002522(n) for n > 1; T(n,2) = A010000(n) = A059100(n) for n > 2; T(n, n-3) = A014209(n-1) for n > 2; T(n, n-2) = A028552(n) for n > 1; T(n, n-1) = A028387(n-1); T(2*n+1, n) = A001107(n+1). - Reinhard Zumkeller, Nov 18 2003
MATHEMATICA
a = Table[n, {n, 0, 200} ]; b = {}; Do[a = Drop[a, {1, n} ]; b = Append[b, Take[a, {1, n} ]]; a = Drop[a, {1, n} ], {n, 1, 14} ]; Flatten[b]
Flatten[Table[Range[n^2, n^2+n-1], {n, 12}]] (* Harvey P. Dale, Dec 18 2015 *)
PROG
(PARI) { n=0; for (m=1, 10^9, s=m^2; a=0; for (k=0, m - 1, a=s+k; write("b064801.txt", n++, " ", a); if (n==1000, return)) ) } \\ Harry J. Smith, Sep 26 2009
(Haskell)
a064801 n = a064801_list !! (n-1)
a064801_list = f 1 [1..] where
f k xs = us ++ f (k + 1) (drop (k + 1) vs)
where (us, vs) = splitAt k xs
-- Reinhard Zumkeller, May 16 2014
CROSSREFS
Cf. A061885 (complement), A253607.
Sequence in context: A115915 A007536 A209887 * A109825 A327175 A193259
KEYWORD
easy,nonn
AUTHOR
Robert G. Wilson v, Oct 21 2001
STATUS
approved

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Last modified March 28 10:55 EDT 2024. Contains 371241 sequences. (Running on oeis4.)