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

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