

A273125


Numbers n for which 3*n is an isolated deficient number.


2



117, 667, 737, 917, 997, 1003, 1083, 1237, 1283, 1503, 1577, 1723, 2077, 2357, 2403, 2637, 2963, 3117, 3197, 3243, 3803, 4583, 4737, 4923, 5717, 5997, 6043, 6197, 6277, 6283, 6517, 6717, 6827, 7163, 7397, 7663, 7723, 7817, 8017, 8563
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OFFSET

1,1


COMMENTS

Numbers n for which 3n2, 3n, and 3n+2 are isolated deficient numbers.
The vast majority of terms (probably around 98.6%) end in either 7 or 3, with a(1) = 117 and a(6) = 1003 being the first instances of each. The first instances of the other digits are: a(91) = 19595, a(187) = 39989, a(213) = 46251. Of the first 151725 terms (those less than 10^8), 74769 end in 7, 670 end in 1, 701 end in 5, 685 end in 9, and 74900 end in 3.


LINKS

Timothy L. Tiffin, Table of n, a(n) for n = 1..151725 [terms < (1/3)*10^8]


EXAMPLE

a(1) = 117 since the following three integers are isolated deficient numbers:
3*117  2 = 349 = A274849(26) = A276049(17) = A133855(16).
3*117 = 351 = A274849(27).
3*117 + 2 = 353 = A274849(28) = A276049(18) = A133855(17).


CROSSREFS

Cf. A133855, A274849, A276049.
Sequence in context: A255022 A217798 A252853 * A327599 A326064 A233376
Adjacent sequences: A273122 A273123 A273124 * A273126 A273127 A273128


KEYWORD

nonn


AUTHOR

Timothy L. Tiffin, Aug 28 2016


STATUS

approved



