%I #21 Dec 30 2016 14:01:09

%S 117,667,737,917,997,1003,1083,1237,1283,1503,1577,1723,2077,2357,

%T 2403,2637,2963,3117,3197,3243,3803,4583,4737,4923,5717,5997,6043,

%U 6197,6277,6283,6517,6717,6827,7163,7397,7663,7723,7817,8017,8563

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

%C Numbers n for which 3n-2, 3n, and 3n+2 are isolated deficient numbers.

%C 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.

%H Timothy L. Tiffin, <a href="/A273125/b273125.txt">Table of n, a(n) for n = 1..151725</a> [terms < (1/3)*10^8]

%e a(1) = 117 since the following three integers are isolated deficient numbers:

%e 3*117 - 2 = 349 = A274849(26) = A276049(17) = A133855(16).

%e 3*117 = 351 = A274849(27).

%e 3*117 + 2 = 353 = A274849(28) = A276049(18) = A133855(17).

%Y Cf. A133855, A274849, A276049.

%K nonn

%O 1,1

%A _Timothy L. Tiffin_, Aug 28 2016