A121031 Multiples of 11 containing an 11 in their decimal representation.

11, 110, 1100, 1111, 1122, 1133, 1144, 1155, 1166, 1177, 1188, 1199, 2112, 2211, 3113, 3311, 4114, 4411, 5115, 5511, 6116, 6611, 7117, 7711, 8118, 8811, 9119, 9911, 11000, 11011, 11022, 11033, 11044, 11055, 11066, 11077, 11088, 11099, 11110

Offset: 1

Author

Reinhard Zumkeller, Jul 21 2006

Keywords

• nonn
• base
• easy

Links

• Harvey P. Dale, Table of n, a(n) for n = 1..1000
• Index entries for 10-automatic sequences.

Crossrefs

Cf. A121041, A008593, A011531, A121022, A121023, A121024, A121025, A121026, A121027, A121028, A121029, A121030, A121032, A121033, A121034, A121035, A121036, A121037, A121038, A121039, A121040.

Programs

Mathematica

Select[11*Range[1100],MemberQ[Partition[IntegerDigits[#],2,1],{1,1}]&] (* Harvey P. Dale, Feb 16 2014 *)
Select[11Range[1100],SequenceCount[IntegerDigits[#],{1,1}]>0&] (* Harvey P. Dale, Jun 14 2024 *)

PARI

is(n)=if(n%11, return(0)); while(n>10, if(n%100==11, return(1)); n\=10); 0 \\ Charles R Greathouse IV, Feb 12 2017

Formula

a(n) ~ 11n. - Charles R Greathouse IV, Feb 12 2017