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A291321
Numbers m with the property that shifting the rightmost digit of m to the left end multiplies the number by 8.
4
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
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).
Sequence in context: A017520 A017652 A168174 * A233479 A368035 A186178
KEYWORD
nonn,base,easy
AUTHOR
Seiichi Manyama, Aug 22 2017
STATUS
approved