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A103184
Primitive sliding numbers (excludes multiples of 10): totals, including repetitions, of sums r + s, r >= s, such that 1/r + 1/s = (r + s)/10^k for some k >= 0.
2
2, 7, 11, 25, 29, 52, 65, 101, 133, 205, 205, 254, 425, 502, 641, 785, 925, 1001, 1258, 2005, 2225, 2504, 3157, 3445, 4025, 5002, 6266, 6325, 8125, 10001, 12508, 15689, 16265, 16625, 20005, 22025, 25004, 31282, 35125, 40025, 50002, 62516
OFFSET
1,1
COMMENTS
See A103182 for further information.
LINKS
Michael De Vlieger, Table of n, a(n) for n = 1..10563 (all terms less than 2*sqrt(10^151))
Michael De Vlieger, Plot of digits of a(n), n = 1..2000, showing zeros in white and nonzero digits in black, 10X horizontal exaggeration.
MATHEMATICA
nn = 8; f[n_] := Transpose@ {Reverse@ #[[1 ;; Ceiling[Length[#]/2]]], #[[-Ceiling[Length[#]/2] ;; -1]]} &@ Divisors[10^n]; TakeWhile[Sort@ Flatten@ Table[Select[Total /@ f[k], ! Divisible[#, 10] &], {k, 0, nn}], # < 2 Sqrt[10^(nn + 1)] &]] (* Michael De Vlieger, Nov 29 2022 *)
CROSSREFS
Sequence in context: A031873 A075356 A235355 * A093039 A201630 A023862
KEYWORD
nonn
AUTHOR
Eric Angelini, Mar 18 2005
EXTENSIONS
More terms from Kerry Mitchell, Mar 09 2005
Name edited by Peter Munn, Nov 27 2022
STATUS
approved