A121040 - OEIS

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A121040

Multiples of 20 containing a 20 in their decimal representation.

20, 120, 200, 220, 320, 420, 520, 620, 720, 820, 920, 1020, 1120, 1200, 1220, 1320, 1420, 1520, 1620, 1720, 1820, 1920, 2000, 2020, 2040, 2060, 2080, 2120, 2200, 2220, 2320, 2420, 2520, 2620, 2720, 2820, 2920, 3020, 3120, 3200, 3220, 3320, 3420, 3520

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

COMMENTS

Not the same as A044352.

LINKS

Table of n, a(n) for n=1..44.

Index entries for 10-automatic sequences.

FORMULA

a(n) ~ 20n. - Charles R Greathouse IV, Feb 12 2017

MATHEMATICA

Select[20*Range[200], SequenceCount[IntegerDigits[#], {2, 0}]>0&] (* The program uses the SequenceCount function from Mathematica version 10 *) (* Harvey P. Dale, Nov 27 2015 *)

PROG

(PARI) is(n)=if(n%20, return(0)); while(n>19, if(n%100==20, return(1)); n\=10); 0 \\ Charles R Greathouse IV, Feb 12 2017

CROSSREFS

Cf. A121041, A008602, A011531, A121022, A121023, A121024, A121025, A121026, A121027, A121028, A121029, A121030, A121031, A121032, A121033, A121034, A121035, A121036, A121037, A121038, A121039.

Sequence in context: A299965 A244289 A293880 * A044352 A044733 A280439

Adjacent sequences: A121037 A121038 A121039 * A121041 A121042 A121043

KEYWORD

nonn,base,easy

AUTHOR

Reinhard Zumkeller, Jul 21 2006

EXTENSIONS

Corrected by T. D. Noe, Oct 25 2006

STATUS

approved