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

Offset

1,3

Links

Table of n, a(n) for n=1..15.

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

Status

approved