cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Previous Showing 21-27 of 27 results.

A293873 Numbers having '13' as substring of their digits.

Original entry on oeis.org

13, 113, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 213, 313, 413, 513, 613, 713, 813, 913, 1013, 1113, 1130, 1131, 1132, 1133, 1134, 1135, 1136, 1137, 1138, 1139, 1213, 1300, 1301, 1302, 1303, 1304, 1305, 1306, 1307, 1308, 1309, 1310, 1311, 1312, 1313, 1314, 1315
Offset: 1

Views

Author

M. F. Hasler, Oct 18 2017

Keywords

Comments

Row 13 of A292690 and A293869. A121033 is the subsequence of multiples of 13.

Crossrefs

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.

Programs

  • Mathematica
    Select[Range[1350],SequenceCount[IntegerDigits[#],{1,3}]>0&] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Dec 31 2017 *)
  • PARI
    is_A293873 = has(n, p=13, m=10^#Str(p))=until(p>n\=10, n%m==p&&return(1))

Formula

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

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

Original entry on oeis.org

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

Views

Author

M. F. Hasler, Oct 18 2017

Keywords

Comments

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

Crossrefs

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.

Programs

  • Mathematica
    Select[Range[2100],SequenceCount[IntegerDigits[#],{2,0}]>0&] (* Harvey P. Dale, Jul 25 2021 *)
  • PARI
    is_A293880 = has(n, p=20, m=10^#Str(p))=until(p>n\=10, n%m==p&&return(1))

Formula

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

A175688 Numbers k with property that arithmetic mean of its digits is both an integer and one of the digits of k.

Original entry on oeis.org

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 22, 33, 44, 55, 66, 77, 88, 99, 102, 111, 120, 123, 132, 135, 147, 153, 159, 174, 195, 201, 204, 210, 213, 222, 231, 234, 240, 243, 246, 258, 264, 285, 306, 312, 315, 321, 324, 333, 342, 345, 351, 354, 357, 360, 369, 375, 396, 402
Offset: 1

Views

Author

Claudio Meller, Aug 09 2010

Keywords

Comments

Subsequence of A061383.
A180160(a(n)) = 0. - Reinhard Zumkeller, Aug 15 2010

Examples

			135 is in the list because (1+3+5)/3 = 3 and 3 is a digit of 135.
		

Crossrefs

Programs

  • Haskell
    a175688 n = a175688_list !! (n-1)
    a175688_list = filter f [0..] where
       f x = m == 0 && ("0123456789" !! avg) `elem` show x
             where (avg, m) = divMod (a007953 x) (a055642 x)
    -- Reinhard Zumkeller, Jun 18 2013
  • Mathematica
    idQ[n_]:=Module[{idn=IntegerDigits[n],m},m=Mean[idn];IntegerQ[m] && MemberQ[idn,m]]; Select[Range[0,500],idQ] (* Harvey P. Dale, Jun 10 2011 *)

Extensions

Edited by Reinhard Zumkeller, Aug 13 2010

A212525 Primes containing a digit 3.

Original entry on oeis.org

3, 13, 23, 31, 37, 43, 53, 73, 83, 103, 113, 131, 137, 139, 163, 173, 193, 223, 233, 239, 263, 283, 293, 307, 311, 313, 317, 331, 337, 347, 349, 353, 359, 367, 373, 379, 383, 389, 397, 431, 433, 439, 443, 463, 503, 523, 563, 593, 613, 631, 643, 653, 673, 683
Offset: 1

Views

Author

Jaroslav Krizek, Jun 12 2012

Keywords

Comments

Supersequence of A045709, A106103 and A106099. Subsequence of A011533 and A062667.

Crossrefs

Cf. A045709 (primes with first digit 3), A011533 (numbers containing a digit 3), A062667 (numbers n such that every divisor of n (except 1) contains the digit 3), A106099 (primes with maximal digit = 3), A106103 (primes with minimal digit = 3), A038611 (primes not containing digit 3).

Programs

  • Mathematica
    Select[Prime[Range[200]], MemberQ[IntegerDigits[#], 3] &] (* T. D. Noe, Jun 12 2012 *)

Formula

a(n) ~ n log n. - Charles R Greathouse IV, Nov 01 2022

A043503 Numbers having three 3's in base 10.

Original entry on oeis.org

333, 1333, 2333, 3033, 3133, 3233, 3303, 3313, 3323, 3330, 3331, 3332, 3334, 3335, 3336, 3337, 3338, 3339, 3343, 3353, 3363, 3373, 3383, 3393, 3433, 3533, 3633, 3733, 3833, 3933, 4333, 5333, 6333, 7333, 8333, 9333, 10333
Offset: 1

Views

Author

Keywords

Crossrefs

Subsequence of A011533.

Programs

  • Mathematica
    Select[Range[11000],DigitCount[#,10,3]==3&] (* Harvey P. Dale, Apr 13 2015 *)

A043502 Numbers having two 3's in base 10.

Original entry on oeis.org

33, 133, 233, 303, 313, 323, 330, 331, 332, 334, 335, 336, 337, 338, 339, 343, 353, 363, 373, 383, 393, 433, 533, 633, 733, 833, 933, 1033, 1133, 1233, 1303, 1313, 1323, 1330, 1331, 1332, 1334, 1335, 1336, 1337, 1338, 1339, 1343
Offset: 1

Views

Author

Keywords

Crossrefs

Subsequence of A011533.

Programs

  • Mathematica
    Select[Range[5000], DigitCount[#, 10, 3]==2&] (* Vincenzo Librandi, Jul 01 2015 *)

A043504 Numbers having four 3's in base 10.

Original entry on oeis.org

3333, 13333, 23333, 30333, 31333, 32333, 33033, 33133, 33233, 33303, 33313, 33323, 33330, 33331, 33332, 33334, 33335, 33336, 33337, 33338, 33339, 33343, 33353, 33363, 33373, 33383, 33393, 33433, 33533, 33633, 33733
Offset: 1

Views

Author

Keywords

Crossrefs

Subsequence of A011533.

Programs

  • Mathematica
    Select[Range[34000],DigitCount[#,10,3]==4&]  (* Harvey P. Dale, Feb 02 2011 *)
Previous Showing 21-27 of 27 results.