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.

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.

Links

Crossrefs

Cf. A007953, A055642, A004426, A004427; A011531, A011532, A011533, A011534, A011535, A011536, A011537, A011538, A011539.
Cf. A052018. - Reinhard Zumkeller, Aug 15 2010

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

A043508 Numbers having four 4's in base 10.

Original entry on oeis.org

4444, 14444, 24444, 34444, 40444, 41444, 42444, 43444, 44044, 44144, 44244, 44344, 44404, 44414, 44424, 44434, 44440, 44441, 44442, 44443, 44445, 44446, 44447, 44448, 44449, 44454, 44464, 44474, 44484, 44494, 44544
Offset: 1

Views

Author

Clark Kimberling

Keywords

Links

Crossrefs

Subsequence of A011534.

Programs

  • Mathematica
    Select[Range[50000], DigitCount[#, 10, 4]==4&] (* Vincenzo Librandi, Jul 01 2015 *)

A284290 Primes containing a digit 4.

Original entry on oeis.org

41, 43, 47, 149, 241, 347, 349, 401, 409, 419, 421, 431, 433, 439, 443, 449, 457, 461, 463, 467, 479, 487, 491, 499, 541, 547, 641, 643, 647, 743, 941, 947, 1049, 1249, 1409, 1423, 1427, 1429, 1433, 1439, 1447, 1451, 1453, 1459, 1471, 1481, 1483, 1487, 1489
Offset: 1

Views

Author

Jaroslav Krizek, Mar 24 2017

Keywords

Comments

Subsequence of A011534 and A062669.

Links

Crossrefs

Cf. Primes containing a digit k for k = 0 - 9: A056709 (k = 0), A208270 (k = 1), A208272 (k = 2), A212525 (k = 3), A284290 (k = 4), A257667 (k = 5), A284291 (k = 6), A257668 (k = 7), A284292 (k = 8), A106093 (k = 9).

Programs

  • Magma
    [p: p in PrimesUpTo(10000) | 4 in Intseq(p)];
  • Mathematica
    Select[Range[1500], PrimeQ[#] && MemberQ[IntegerDigits[#], 4] &] (* Amiram Eldar, Nov 09 2019 *)

A043506 Numbers having two 4's in base 10.

Original entry on oeis.org

44, 144, 244, 344, 404, 414, 424, 434, 440, 441, 442, 443, 445, 446, 447, 448, 449, 454, 464, 474, 484, 494, 544, 644, 744, 844, 944, 1044, 1144, 1244, 1344, 1404, 1414, 1424, 1434, 1440, 1441, 1442, 1443, 1445, 1446, 1447, 1448
Offset: 1

Views

Author

Clark Kimberling

Keywords

Links

Crossrefs

Cf. A043498.
Subsequence of A011534.

Programs

  • Mathematica
    Select[Range[100000], DigitCount[#, 10, 4] == 2 &] (* Vincenzo Librandi, Nov 20 2015 *)
  • PARI
    c(k, d, b) = {my(c=0, f); while (k>b-1, f=k-b*(k\b); if (f==d, c++); k\=b); if (k==d, c++); return(c)}
for(n=0, 2000, if(c(n, 4, 10)==2, print1(n, ", "))) \\ Altug Alkan, Nov 20 2015

A043507 Numbers having three 4's in base 10.

Original entry on oeis.org

444, 1444, 2444, 3444, 4044, 4144, 4244, 4344, 4404, 4414, 4424, 4434, 4440, 4441, 4442, 4443, 4445, 4446, 4447, 4448, 4449, 4454, 4464, 4474, 4484, 4494, 4544, 4644, 4744, 4844, 4944, 5444, 6444, 7444, 8444, 9444, 10444
Offset: 1

Views

Author

Clark Kimberling

Keywords

Links

Crossrefs

Subsequence of A011534.

Programs

  • Mathematica
    Select[Range[11000],DigitCount[#,10,4]==3&] (* Harvey P. Dale, Aug 17 2020 *)

A095790 Numbers whose name in English contains an "r".

Original entry on oeis.org

3, 4, 13, 14, 23, 24, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 53, 54, 63, 64, 73, 74, 83, 84, 93, 94, 103, 104, 113, 114, 123, 124, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145, 146, 147, 148
Offset: 1

Views

Author

Michael Joseph Halm, Jul 10 2004

Keywords

Comments

A008520 are numbers which contain an "e", A008540 an "f", A011538 a "g", A008536 an "n", A008519 an "o", A008538 an "s", A008522 a "t", A011534 a "u", A011532 a "w", A011536 an "x" and A008553 a "y"

Examples

			a(1) = 3 because "three" contains an "r", 0, 1 and 2 do not

Crossrefs

Cf. A008520, A008540, A011538, A008536, A008519, A008538, A008522, A011534, A011532, A011536, A008553.

A095798 Numbers whose name in English contains a "v".

Original entry on oeis.org

5, 7, 11, 12, 17, 25, 27, 35, 37, 45, 47, 55, 57, 65, 67, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 85, 87, 95, 97, 105, 107, 111, 112, 117, 125, 127, 135, 137, 145, 147, 155, 157, 165, 167, 170, 171, 172, 173, 174, 175, 176, 177, 178, 179, 185, 187, 195, 197, 205, 207
Offset: 1

Views

Author

Michael Joseph Halm, Jul 10 2004

Keywords

Comments

A008520 are numbers which contain an "e", A008540 an "f", A011538 a "g", A008536 an "n", A008519 an "o", A008538 an "s", A008522 a "t", A011534 a "u", A011532 a "w", A011536 an "x" and A008553 a "y"

Examples

			a(3) = 11 because "eleven" contains a "v" and it is the third number to do so (after "five" and "seven").

Crossrefs

Cf. A008520, A008540, A011538, A008536, A008519, A008538, A008522, A011534, A011532, A011536, A008553.

Extensions

Corrected by Rick L. Shepherd, Jul 10 2004
Previous Showing 21-27 of 27 results.

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