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A208259 Numbers starting and ending with digit 1. 8
1, 11, 101, 111, 121, 131, 141, 151, 161, 171, 181, 191, 1001, 1011, 1021, 1031, 1041, 1051, 1061, 1071, 1081, 1091, 1101, 1111, 1121, 1131, 1141, 1151, 1161, 1171, 1181, 1191, 1201, 1211, 1221, 1231, 1241, 1251, 1261, 1271, 1281, 1291, 1301, 1311, 1321, 1331 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
Union of A062332 and A208260. Supersequence of A208262 (numbers with all divisors starting and ending with digit 1).
Intersection of A017281 and A131835; A000030(a(n)) = a(n) mod 10 = 1. - Reinhard Zumkeller, Jul 16 2014
LINKS
MATHEMATICA
Select[Range[2000], First[IntegerDigits[#]] == 1 && Last[IntegerDigits[#]] == 1 &] (* Vladimir Joseph Stephan Orlovsky, Feb 26 2012 *)
PROG
(Haskell)
a208259 n = a208259_list !! (n-1)
a208259_list = 1 : map ((+ 1) . (* 10)) a131835_list
-- Reinhard Zumkeller, Jul 16 2014
CROSSREFS
Cf. A062332 (primes starting and ending with a digit 1), A208260 (nonprime numbers starting and ending with a digit 1).
Sequence in context: A038444 A115824 A364326 * A043036 A072001 A265510
KEYWORD
nonn,base
AUTHOR
Jaroslav Krizek, Feb 24 2012
STATUS
approved

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Last modified June 19 19:59 EDT 2024. Contains 373507 sequences. (Running on oeis4.)