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A098326 Recurrence derived from the decimal places of sqrt(2). a(0)=0, a(i+1)=position of first occurrence of a(i) in decimal places of sqrt(2). 5
0, 13, 5, 7, 11, 186, 239, 336, 1284, 5889, 11708, 70286, 19276, 35435, 22479, 42202, 28785, 107081, 973876, 1187108 (list; graph; refs; listen; history; text; internal format)



Table of n, a(n) for n=0..19.



So for example a(2)=13 because 13th decimal place of sqrt(2) is 0; then a(3)=5 because 13 is found starting at the 5th decimal place; a(4)=7 because 5 is at the 7th decimal place and so on.


with(StringTools): Digits:=10000: G:=convert(evalf(sqrt(2)), string): a[0]:=0: for n from 1 to 10 do a[n]:=Search(convert(a[n-1], string), G)-2:printf("%d, ", a[n-1]):od: # Nathaniel Johnston, Apr 30 2011


Other recurrence sequences: A097614 for Pi, A098266 for e, A098289 for log(2), A098290 for Zeta(3), A098319 for 1/Pi, A098320 for 1/e, A098321 for gamma, A098322 for G, A098323 for 1/G, A098324 for Golden Ratio (phi), A098325 for sqrt(Pi), A120482 for sqrt(3), A189893 for sqrt(5). A002193 for digits of sqrt(2).

Sequence in context: A107833 A248146 A097484 * A302208 A068662 A235366

Adjacent sequences:  A098323 A098324 A098325 * A098327 A098328 A098329




Mark Hudson (mrmarkhudson(AT)hotmail.com), Sep 13 2004


a(18)-a(19) from Nathaniel Johnston, Apr 30 2011



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Last modified December 8 17:36 EST 2019. Contains 329865 sequences. (Running on oeis4.)