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A247345 a(1) = 16. For n > 1, a(n) is the position of the first occurrence of a(n-1) after the decimal point in the decimal expansion of Pi. 1
16, 40, 70, 96, 180, 3664, 24717, 15492, 84198, 65489, 3725, 16974, 41702, 3788, 5757, 1958, 14609, 62892, 44745, 9385, 169, 40, 70, 96, 180, 3664, 24717, 15492, 84198, 65489, 3725, 16974, 41702, 3788, 5757, 1958, 14609, 62892, 44745, 9385, 169, 40, 70, 96 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

After the first term, the sequence enters a repeating cycle of length 20.

According to the information on the website of Anderson, this sequence was discovered earlier by Dan Sikorsky.

First element a(1) = 61 leads after seven steps 61, 219, 716, 39, 43, 23, 16, ... into the same repeating cycle, same with a(1) = 71 after five steps 71, 39, 43, 23, 16, ... - Martin Renner, Feb 22 2020

LINKS

Table of n, a(n) for n=1..44.

D. Andersen, Loop Sequences within Pi, The Pi-Search Page.

MATHEMATICA

L={16}; pi=ToString[ FromDigits@ RealDigits[Pi-3, 10, 10^5 ][[1]]]; Do[

AppendTo[L, StringPosition[ pi, ToString@ Last@ L, 1][[1, 1]]], {23}]; L (* Giovanni Resta, Jul 26 2015 *)

CROSSREFS

Cf. A000796, A097614.

Sequence in context: A132161 A316562 A221684 * A332519 A177723 A174321

Adjacent sequences:  A247342 A247343 A247344 * A247346 A247347 A247348

KEYWORD

nonn,base

AUTHOR

Felix Fröhlich, Jul 26 2015

STATUS

approved

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Last modified October 5 05:10 EDT 2022. Contains 357252 sequences. (Running on oeis4.)