A293879 -id:A293879 - cp's OEIS frontend

A293880 Numbers having '20' as substring of their digits.

20, 120, 200, 201, 202, 203, 204, 205, 206, 207, 208, 209, 220, 320, 420, 520, 620, 720, 820, 920, 1020, 1120, 1200, 1201, 1202, 1203, 1204, 1205, 1206, 1207, 1208, 1209, 1220, 1320, 1420, 1520, 1620, 1720, 1820, 1920, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010

Offset: 1

M. F. Hasler, Oct 18 2017

Row 20 of A292690 and A293869. A121040 lists the terms which are divisible by 19.

Index entries for 10-automatic sequences

Cf. A292690, A293869.
Cf. A011540, A011531, A011532, A011533, A011534, A011535, A011536, A011537, A011538, A011539: analog for '0' - '9'.
Cf. A293870, A293871, A293872, A293873, A293874, A293875, A293876, A293877, A293878, A293879: same for '10' - '19'.
Cf. A121041, A121022, A121023, A121024, A121025, A121026, A121027, A121028, A121029, A121030, A121031, A121032, A121033, A121034, A121035, A121036, A121037, A121038, A121039, A121040: subsequences of the above, containing only multiples of the pattern p.

Select[Range[2100],SequenceCount[IntegerDigits[#],{2,0}]>0&] (* Harvey P. Dale, Jul 25 2021 *)

is_A293880 = has(n, p=20, m=10^#Str(p))=until(p>n\=10, n%m==p&&return(1))

a(n) ~ n. - Charles R Greathouse IV, Nov 02 2022

A121669 Numbers with sum of digits = 19, divisible by 19 and containing the string "19".

Original entry on oeis.org

17119, 19171, 19342, 19513, 20197, 21907, 33193, 34219, 41914, 51319, 61921, 101935, 102619, 112195, 119035, 119206, 121942, 125191, 171019, 171190, 190171, 190342, 190513, 191026, 191710, 192052, 192223, 193420, 194104, 195130, 195301, 197011, 201970, 204193

Offset: 1

Hassan Taifour (hytaifour(AT)yahoo.co.uk), Sep 10 2006

Conjecture: There are approximately k(n-1)(n-2)^(n-2) terms of this sequence up to 10^n, where k is about e/(19e-19). - Charles R Greathouse IV, Oct 13 2022

Chai Wah Wu, Table of n, a(n) for n = 1..12794 (all terms < 10^11)

Intersection of A008601, A166459 and A293879.

d19Q[n_]:=Module[{idn=IntegerDigits[n]},Total[idn]==19&&MemberQ[ Partition[ idn,2,1],{1,9}]]; Select[19*Range[20000],d19Q] (* Harvey P. Dale, Jun 10 2014 *)

def ok(n): s = str(n); return n%19==0 and '19' in s and sum(map(int, s))==19
print(list(filter(ok, range(205000)))) # Michael S. Branicky, Aug 06 2021

More terms from Zak Seidov, Sep 12 2006

cp's OEIS Frontend

A293880 Numbers having '20' as substring of their digits.

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