A215737 a(n) is the first digit to appear n times in succession in a power of 11.

1, 1, 8, 7, 6, 0, 6, 0, 9, 6, 6, 2, 2, 7, 6, 9

Offset

1,3

Links

Table of n, a(n) for n=1..16.

Mathematica

n = 1; x = 1; lst = {};
For[i = 1, i <= 10000, i++,
z = Split[IntegerDigits[x]]; a = Length /@ z; b = Max[a];
For[j = n, j <= b, j++,
  AppendTo[lst, First[First[Part[z, First[Position[a, b]]]]]]; n++
]; x = 11 x ]; lst  (* Robert Price, Mar 16 2019 *)

Prog

(Python)
def A215737(n):
    a, s = 1, tuple(str(i)*n for i in range(10))
    while True:
        a *= 11
        t = str(a)
        for i, x in enumerate(s):
            if x in t:
                return i # Chai Wah Wu, Mar 30 2021

Crossrefs

Cf. A001020 (powers of 11), A045875, A215731, A215732.

Sequence in context: A195846 A201666 A349250 * A154718 A334424 A021537

Adjacent sequences: A215734 A215735 A215736 * A215738 A215739 A215740

Keyword

nonn,more,base

Author

V. Raman, Aug 22 2012

Extensions

a(10)-a(13) added by V. Raman, Apr 30 2012, in correspondence with A215731.

a(14) from Giovanni Resta, Apr 18 2016

a(15) from Bert Dobbelaere, Feb 15 2019

a(16) from Paul Geneau de Lamarlière, Oct 03 2024

Status

approved