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 1-10 of 23 results. Next

A240755 Smallest prime which occurs in prime power factorization of A240751(n)! with exponent n.

Original entry on oeis.org

2, 3, 2, 2, 3, 3, 2, 2, 3, 2, 2, 5, 3, 3, 2, 2, 3, 2, 2, 5, 3, 2, 2, 5, 2, 2, 3, 3, 7, 3, 2, 2, 5, 2, 2, 3, 5, 2, 2, 3, 2, 2, 5, 3, 3, 2, 2, 3, 2, 2, 5, 5, 2, 2, 3, 2, 2, 3, 3, 7, 3, 3, 2, 2, 5, 2, 2, 3, 5, 2, 2, 3, 2, 2, 3, 3, 5, 2, 2, 3, 2, 2, 5, 3, 2, 2, 5
Offset: 1

Views

Author

Vladimir Shevelev, Apr 12 2014

Keywords

Examples

			A240751(4)=6, since 6!=2^4*3^2*5. Here, only the prime 2 is in power 4, thus A240755(4)=2.
		

Crossrefs

Formula

a(n)^n || A240751(n)!.

Extensions

More terms from Peter J. C. Moses, Apr 12 2014

A240764 Least k such that prime power factorization of A240751(k)! contains p^k when the smallest such p equals prime(n), or a(n)=0 if there is no such k.

Original entry on oeis.org

1, 2, 12, 29, 186, 2865, 3265, 379852, 7172525
Offset: 1

Views

Author

Vladimir Shevelev, Apr 12 2014

Keywords

Comments

The first position k in A240755 in which A240755(k) = prime(n), or a(n)=0 if prime(n) does not occur in A240755.
Conjecture: all a(n)>0.

Examples

			A240751(a(3))! = A240751(12)! = 50!. 50! is the least factorial having exponent 12 in its prime factorization. That exponent denotes the multiplicity of prime(3) = 5. - _David A. Corneth_, Mar 27 2017
		

Crossrefs

Extensions

a(5)-a(7) from Peter J. C. Moses, Apr 14 2014
a(8)-a(9) from David A. Corneth, Mar 27 2017

A286003 Numbers n such that 3^n is the highest power of 3 dividing A240751(n).

Original entry on oeis.org

2, 5, 6, 9, 13, 14, 17, 21, 27, 28, 30, 36, 40, 44, 45, 48, 55, 58, 59, 61, 62, 68, 72, 75, 76, 80, 84, 90, 93, 99, 103, 106, 107, 108, 111, 114, 115, 121, 122, 123, 125, 126, 129, 136, 139, 140, 144, 147, 148, 151, 155, 156, 157, 163, 167, 170, 171, 175, 178, 179
Offset: 1

Views

Author

David A. Corneth, Apr 30 2017

Keywords

Comments

Is A005187 the same as values n such that 2^n||A240751(n)?

Crossrefs

A286010 Numbers n such that 23^n is the highest power of 23 dividing A240751(n).

Original entry on oeis.org

7172525, 15122988, 21210412, 48538612, 48752905, 51466002, 52658325, 55938150, 57611786, 73564837, 79352750, 83297618, 87015476, 96850742, 101001720, 112873406, 112907600, 122331745, 131633392, 132790999, 135376501, 141763112, 148650650, 156434774, 173413868, 177310781, 180684007, 190994768
Offset: 1

Views

Author

David A. Corneth, May 01 2017

Keywords

Comments

No terms for "Numbers n such that 29^n is the highest power of 29 dividing A240751(n)." up to 10^8.

Crossrefs

A284050 a(n) = floor(A240751(n) / n), where A240751(n) = the smallest k such that in the prime power factorization of k! there exists at least one exponent n.

Original entry on oeis.org

2, 3, 1, 1, 2, 2, 1, 1, 2, 1, 1, 4, 2, 2, 1, 1, 2, 1, 1, 4, 2, 1, 1, 4, 1, 1, 2, 2, 6, 2, 1, 1, 4, 1, 1, 2, 4, 1, 1, 2, 1, 1, 4, 2, 2, 1, 1, 2, 1, 1, 4, 4, 1, 1, 2, 1, 1, 2, 2, 6, 2, 2, 1, 1, 4, 1, 1, 2, 4, 1, 1, 2, 1, 1, 2, 2, 4, 1, 1, 2, 1, 1, 4, 2, 1, 1, 4
Offset: 1

Views

Author

David A. Corneth, Mar 19 2017

Keywords

Comments

For n > 2, p = a(n) + 1 is the prime that has exponent n in A240751(n)! (see A240751 for an outline of a proof).
First occurrence of p-1: 1, 2, 12, 29, 186, 2865, 3265, 379852, 7172525, ..., (A240764). - Robert G. Wilson v, Apr 15 2017. Comment changed by David A. Corneth, Apr 15 2017

Examples

			For n = 5, p = a(n) + 1 = 3 is the prime such that A240751(5)! = 12! is the least factorial that has exponent 5.
		

Crossrefs

Programs

  • Mathematica
    Table[k = 2; While[! MemberQ[FactorInteger[k!][[All, -1]], n], k++]; Floor[k/n], {n, 87}] (* Michael De Vlieger, Mar 24 2017 *)
  • PARI
    a(n) = A240751(n)\n \\ (for computation of A240751(n), see A240751)

Formula

A240751(n) = n*a(n) + A284051(n). - Antti Karttunen, Mar 22 2017
a(n) = A240755(n) - 1 for n > 2 and a(n) = A240755(n) for n < 3. I.e., A240755(n) - A157928(n+1). - David A. Corneth, Mar 27 2017

A284051 a(n) = A240751(n) mod n, where A240751(n) = the smallest k such that in the prime power factorization of k! there exists at least one exponent n.

Original entry on oeis.org

0, 0, 1, 2, 2, 3, 1, 2, 3, 2, 3, 2, 1, 2, 1, 2, 2, 2, 3, 5, 3, 2, 3, 4, 3, 4, 3, 4, 8, 3, 1, 2, 3, 2, 3, 6, 2, 2, 3, 1, 3, 4, 3, 2, 3, 2, 3, 3, 3, 4, 6, 7, 3, 4, 4, 4, 5, 4, 5, 4, 4, 5, 1, 2, 5, 2, 3, 5, 4, 2, 3, 6, 3, 4, 6, 7, 7, 2, 3, 2, 3, 4, 8, 3, 3, 4, 7
Offset: 1

Views

Author

David A. Corneth, Mar 19 2017

Keywords

Examples

			A240751(5) = 12 so a(5) = 12 mod 5 == 2.
		

Crossrefs

Programs

  • Mathematica
    Table[k = 2; While[! MemberQ[FactorInteger[k!][[All, -1]], n], k++]; Mod[k, n], {n, 87}] (* Michael De Vlieger, Mar 24 2017 *)
  • PARI
    a(n) = A240751(n)%n \\ (For computation of A240751(n), see A240751)

Formula

A240751(n) = n*A284050(n) + a(n). - Antti Karttunen, Mar 22 2017

A286005 Numbers n such that 7^n is the highest power of 7 dividing A240751(n).

Original entry on oeis.org

29, 60, 91, 92, 141, 154, 185, 204, 217, 241, 254, 279, 285, 342, 403, 441, 473, 497, 510, 528, 541, 572, 603, 622, 666, 697, 715, 753, 771, 779, 780, 811, 841, 873, 922, 936, 954, 973, 1022, 1047, 1053, 1066, 1091, 1122, 1234, 1291, 1347, 1404, 1422, 1453, 1496, 1561
Offset: 1

Views

Author

David A. Corneth, May 01 2017

Keywords

Crossrefs

A286006 Numbers n such that 11^n is the highest power of 11 dividing A240751(n).

Original entry on oeis.org

186, 447, 635, 765, 1035, 1092, 1378, 1435, 1540, 2015, 2553, 2740, 2808, 3027, 4154, 4465, 4497, 4603, 4766, 4816, 4897, 5084, 5166, 5265, 5403, 5590, 5666, 5747, 5828, 6245, 6515, 6572, 6759, 6809, 7029, 7559, 7690, 7991, 8459, 8810, 8859, 9202, 9234, 9340, 9821
Offset: 1

Views

Author

David A. Corneth, May 01 2017

Keywords

Crossrefs

A286004 Numbers n such that 5^n is the highest power of 5 dividing A240751(n).

Original entry on oeis.org

12, 20, 24, 33, 37, 43, 51, 52, 65, 69, 77, 83, 87, 96, 100, 118, 124, 132, 133, 160, 164, 172, 199, 226, 230, 234, 238, 245, 249, 253, 267, 275, 298, 306, 307, 315, 320, 338, 346, 347, 351, 355, 361, 362, 363, 376, 380, 384, 388, 402, 411, 415, 433, 437, 442, 443, 451
Offset: 1

Views

Author

David A. Corneth, May 01 2017

Keywords

Crossrefs

A286007 Numbers n such that 13^n is the highest power of 13 dividing A240751(n).

Original entry on oeis.org

2865, 3640, 3942, 4922, 6677, 7959, 10972, 11577, 11928, 12859, 18233, 19213, 22153, 30295, 30646, 31977, 34664, 35620, 36527, 44440, 49764, 51520, 54182, 55439, 55839, 56045, 56951, 60340, 60920, 63909, 64308, 64890, 66995, 68278, 70540, 72246, 76795, 77195, 77595
Offset: 1

Views

Author

David A. Corneth, May 01 2017

Keywords

Crossrefs

Showing 1-10 of 23 results. Next