login
A279426
Numbers k such that k^2 has an odd number of digits and the middle digit is 6.
3
13, 19, 31, 103, 108, 117, 121, 125, 129, 133, 140, 147, 157, 160, 175, 178, 194, 199, 204, 209, 216, 225, 236, 238, 240, 260, 262, 264, 275, 284, 291, 296, 301, 306, 1003, 1008, 1013, 1018, 1023, 1028, 1047, 1052, 1066, 1080, 1094, 1103, 1112, 1121, 1130
OFFSET
1,1
LINKS
EXAMPLE
13^2 = 1(6)9, 133^2 = 17(6)89, 284^2 = 80(6)56.
MATHEMATICA
Select[Range[1200], OddQ[IntegerLength[#^2]]&&IntegerDigits[#^2][[(IntegerLength[ #^2]+1)/2]] == 6&] (* Harvey P. Dale, May 28 2023 *)
CROSSREFS
KEYWORD
nonn,base,easy
AUTHOR
Lars Blomberg, Dec 22 2016
STATUS
approved