A153220 - OEIS

A153220

Self-locating strings within Pi: numbers n such that the string n is at position n (counting 3 and the decimal point) in decimal digits of Pi.

4, 315, 360, 384, 47696, 496498, 1577526

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

COMMENTS

a(8) > 10^9. - Vaclav Kotesovec, Feb 18 2020

LINKS

Table of n, a(n) for n=1..7.

EXAMPLE

a(1)=4 because the 4th character (including the decimal point) in 3.14159... is also a 4.

MATHEMATICA

dpi = RealDigits[Pi, 10, 10000010][[1]]; Select[Range[2, 10000000], FromDigits[Take[dpi, {# - 1, # - 2 + IntegerLength[#]}]] == # &] (* Vaclav Kotesovec, Feb 18 2020 *)

CROSSREFS

Cf. A057679, A057680, A109513, A109514

Sequence in context: A201979 A280792 A027512 * A227673 A203479 A034226

Adjacent sequences: A153217 A153218 A153219 * A153221 A153222 A153223

KEYWORD

base,more,nonn

AUTHOR

Gil Broussard, Dec 21 2008

EXTENSIONS

a(7) from Vaclav Kotesovec, Feb 18 2020

STATUS

approved