A392198 Position of the first instance of n, expressed in hexadecimal, in the hexadecimal representation of Pi.

13, 17, 1, 0, 2, 10, 5, 27, 7, 20, 6, 81, 58, 15, 24, 4, 148, 489, 202, 17, 412, 250, 131, 127, 290, 19, 171, 143, 754, 46, 70, 228, 245, 69, 39, 343, 1, 314, 187, 415, 67, 41, 329, 529, 203, 166, 23, 161, 12, 16, 0, 268, 30, 1446, 242, 26, 37, 218, 379, 512

Offset

0,1

Comments

Hexadecimal Pi begins as: 3.243F6A8885A308D313198A2E. The leading "3" value is at position 0. The hexadecimal point is not counted, e.g., the hex number A is at position 6.

Links

Michael S. Branicky, Table of n, a(n) for n = 0..10000

James S. DeArmon, R Code for A392198

Example

a(0)=13, since 0 is at position 13.

Mathematica

d=4000 (* increase d for n>257 *); a[n_]:=SequencePosition[RealDigits[Pi, 16, d][[1]], IntegerDigits[n, 16]][[1, 1]]-1; Array[a, 60, 0] (* James C. McMahon, Mar 06 2026 *)

Prog

(R) # See Links.
(PARI) lista(nn)= localprec(nn*1000); my(p=binary(Pi), a=List()); listput(~a, fromdigits(p[1], 2)); p=p[2]; forstep(i=1, #p-3, 4, listput(~a, fromdigits(p[i..i+3], 2))); p=Vec(a); a=List(); for(i=0, nn-1, my(d=if(i, digits(i, 16), [0])); for(j=1, #p, if(d==p[j..j+#d-1], listput(~a, j-1); break))); Vec(a); \\ Ruud H.G. van Tol, Mar 06 2026

Crossrefs

Cf. A014777, A062964, A099333, A178707, A385936.

Sequence in context: A107081 A029526 A219949 * A173632 A061060 A084307

Adjacent sequences: A392195 A392196 A392197 * A392199 A392200 A392201

Keyword

nonn,base

Author

James S. DeArmon, Jan 31 2026

Status

approved