A291321 Numbers m with the property that shifting the rightmost digit of m to the left end multiplies the number by 8.

1012658227848, 1139240506329, 10126582278481012658227848, 11392405063291139240506329, 101265822784810126582278481012658227848, 113924050632911392405063291139240506329, 1012658227848101265822784810126582278481012658227848

Offset

1,1

Comments

x = (10^12 - 8)/79 = 12658227848.

a(1) = 8*x*10 + 8, a(2) = 9*x*10 + 9.

Links

Seiichi Manyama, Table of n, a(n) for n = 1..152

Wikipedia, Parasitic number.

Formula

a(2*k - 1) = 8*(10^(13*k) - 1)/79.

a(2*k) = 9*(10^(13*k) - 1)/79.

Example

b = 101265822784.
a(1) = b*10 + 8,
8*a(1) = 8101265822784 = 8*10^12 + b.

Prog

(PARI) a(n)=10^((n+1)\2*13)\79*(9-n%2) \\ Charles R Greathouse IV, Aug 23 2017

Crossrefs

Cf. A146088 (k=2), A146561 (k=3), A146569 (k=4), A146754 (k=5), A291354 (k=6), A291215 (k=7), this sequence (k=8), A291353 (k=9).

Cf. A092697, A097717.

Sequence in context: A017520 A017652 A168174 * A233479 A368035 A186178

Adjacent sequences: A291318 A291319 A291320 * A291322 A291323 A291324

Keyword

nonn,base,easy

Author

Seiichi Manyama, Aug 22 2017

Status

approved