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.

Showing 1-4 of 4 results.

A182040 Integers whose decimal representation consists of three distinct digits, one appearing once, one appearing twice, and one appearing three times.

Original entry on oeis.org

100012, 100013, 100014, 100015, 100016, 100017, 100018, 100019, 100021, 100022, 100031, 100033, 100041, 100044, 100051, 100055, 100061, 100066, 100071, 100077, 100081, 100088, 100091, 100099, 100102, 100103, 100104, 100105, 100106, 100107, 100108, 100109, 100112
Offset: 1

Views

Author

Jonathan Vos Post, Apr 09 2012

Keywords

Comments

There are 38880 terms, including 41 squares (A182098) and 3640 primes (A182092). - Zak Seidov, Apr 12 2012
This is the subsequence of A218556 consisting of terms with indices n = 254, ..., 39133. The number of terms is 38880 = A218566(10,3), the starting index is 254 = 1 + A218566(10,1) + A218566(10,2) + 1. - M. F. Hasler, Nov 02 2012

Crossrefs

Cf. A071925, A181986 (digitally balanced numbers: ternary numbers which have the same number of 0's as 1's as 2's), A182051 (primes with a majority of one digit).

Programs

  • Mathematica
    t = Select[Range[100000, 999999], Sort[Transpose[Tally[IntegerDigits[#]]][[2]]] == {1, 2, 3} &]; Take[t, 32] (* T. D. Noe, Apr 11 2012 *)
  • PARI
    is(n)=n=vecsort(eval(Vec(Str(n))));vecsort(apply(k->sum(i=1, #n,n[i]==k),vecsort(n,,8)))==[1,2,3] \\ Charles R Greathouse IV, Apr 11 2012

A182092 Primes in A182040.

Original entry on oeis.org

100019, 100103, 100109, 100151, 100333, 100411, 100501, 100511, 100801, 100811, 100999, 101009, 101021, 101051, 101081, 101107, 101221, 101333, 101501, 101701, 101771, 101999, 102001, 102101, 102121, 103001, 106661, 107077, 107101, 107171, 107717, 108011
Offset: 1

Views

Author

Jonathan Vos Post, Apr 11 2012

Keywords

Comments

Primes whose decimal representation consists of three distinct digits, one appearing once, one appearing twice, and one appearing three times.
There are 3640 terms.
The subsequence of emirps begins 100411, since 114001 is prime; 100511, since 115001 is prime; 100999, since 999101 is prime; 101333, since 333101 is prime; 101701, since 107101 is prime; 101999, since 999101 is prime.

Crossrefs

Cf. A000040, A182040, A182051 (primes with a majority of one digit).

Programs

Formula

A000040 INTERSECTION A182040.

A216203 Smallest prime that does not divide at least one n-digit zeroless pandigital number.

Original entry on oeis.org

44449, 900001, 7000003, 20000003, 30000001, 100000007, 500000003, 1000000007, 6000000001
Offset: 9

Views

Author

Arkadiusz Wesolowski, Mar 12 2013

Keywords

Comments

How many first terms are in A182051?
The analogous sequence for pandigital numbers is A228253. - Giovanni Resta, Aug 19 2013

Crossrefs

Programs

  • Mathematica
    lst = Times @@ Union[FromDigits@# & /@ Permutations@Range[9]]; n = 1; While[True, p = Prime[n]; If[! Divisible[lst, p], Print[p]; Break[]]; n++]

Extensions

a(11)-a(16) from Giovanni Resta, Mar 12 2013
a(17) from Giovanni Resta, Mar 13 2013

A228253 Smallest prime that does not divide at least one n-digit pandigital number.

Original entry on oeis.org

111119, 4999999, 66666667, 666666667, 9000100009, 66666666667
Offset: 10

Views

Author

Keywords

Crossrefs

Showing 1-4 of 4 results.