A208262 Numbers with all divisors starting and ending with digit 1.

1, 11, 101, 121, 131, 151, 181, 191, 1021, 1031, 1051, 1061, 1091, 1111, 1151, 1171, 1181, 1201, 1231, 1291, 1301, 1321, 1331, 1361, 1381, 1441, 1451, 1471, 1481, 1511, 1531, 1571, 1601, 1621, 1661, 1721, 1741, 1801, 1811, 1831, 1861, 1871, 1901, 1931, 1951, 1991

Offset: 1

Author

Jaroslav Krizek, Feb 24 2012

Keywords

• nonn
• base

Comments

Union of A062332 and A208261. Subsequence of A208259 (numbers starting and ending with digit 1).

Examples

			Divisors of 1111: 1, 11, 101, 1111.
		

Crossrefs

Cf. A062332 (primes starting and ending with digit 1), A208261 (nonprime numbers with all divisors starting and ending with digit 1).

Programs

Mathematica

Select[Table[n, {n, 2000}], Union[First /@ IntegerDigits[Divisors[#]]] == {1} && Union[Last /@ IntegerDigits[Divisors[#]]] == {1} &] (* Vladimir Joseph Stephan Orlovsky, Feb 26 2012 *)