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A076287
Numbers of the form (8^{mr}-1)/(8^r-1) for positive integers m, r.
8
1, 9, 65, 73, 513, 585, 4097, 4161, 4681, 32769, 37449, 262145, 262657, 266305, 299593, 2097153, 2396745, 16777217, 16781313, 17043521, 19173961, 134217729, 134480385, 153391689, 1073741825, 1073774593, 1090785345, 1227133513, 8589934593, 9817068105
OFFSET
1,2
COMMENTS
Numbers which in base 8 contain only 0's and 1's, with equally spaced 1's. - Robert Israel, Jan 15 2019
LINKS
T. Chinburg and M. Henriksen, Sums of k-th powers in the ring of polynomials with integer coefficients, Acta Arithmetica, 29 (1976), 227-250.
MAPLE
1, seq(seq((8^(k+r)-1)/(8^r-1), r = ListTools:-Reverse(sort(convert(numtheory:-divisors(k), list)))), k=1..20); # Robert Israel, Jan 15 2019
CROSSREFS
Cf. A064896 (k=2), A076270 (k=3), A076275 (k=4), A076284 (k=5), A076285 (k=6), A076286 (k=7), A076288 (k=9), A076289 (k=10).
Sequence in context: A043426 A038484 A043021 * A339997 A226929 A212668
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Nov 06 2002
STATUS
approved