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A171887 Records in A171868 (positions). 3
1, 2, 4, 9, 20, 50, 147, 269, 992, 1000, 4297, 76468, 97314 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..13.

PROG

(Python)

A181391_list, A171887_list, l, r, k = [0, 0], [1], 0, 1, 1

for n in range(1, 10**6):

....for m in range(n-1, -1, -1):

........if A181391_list[m] == A181391_list[n]:

............A181391_list.append(n-m)

............break

....else:

........A181391_list.append(0)

........k += 1

........if n-l > r:

............r = n-l

............A171887_list.append(k)

........l = n # Chai Wah Wu, Jan 02 2015

CROSSREFS

Cf. A181391, A171868, A171888.

Sequence in context: A006648 A128496 A134955 * A027881 A002861 A032200

Adjacent sequences:  A171884 A171885 A171886 * A171888 A171889 A171890

KEYWORD

nonn,more

AUTHOR

N. J. A. Sloane, Oct 18 2010

EXTENSIONS

a(12)-a(13) from Chai Wah Wu, Jan 02 2015

STATUS

approved

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Last modified March 21 01:18 EDT 2019. Contains 321356 sequences. (Running on oeis4.)