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 1-8 of 8 results.

A256884 Numbers divisible by prime(d+1) for each digit d of their base-4 representation.

Original entry on oeis.org

0, 10, 21, 40, 63, 84, 90, 105, 130, 140, 150, 160, 165, 170, 175, 210, 252, 276, 324, 330, 336, 345, 360, 390, 405, 420, 520, 560, 600, 630, 640, 650, 660, 680, 700, 735, 770, 840, 861, 910, 1008, 1044, 1050, 1092, 1104, 1110, 1170, 1260, 1284, 1290, 1296, 1320, 1344, 1350, 1365, 1380, 1407, 1410, 1440, 1470, 1533, 1560, 1620
Offset: 1

Views

Author

M. F. Hasler, Apr 11 2015

Keywords

Comments

The base-4 variant of A256882, A256883, A256865, ..., A256870 in bases 2, ..., 10.
A variant of A256874 where digits 0 are forbidden and divisibility by prime(d) is required.

Examples

			0 is divisible by prime(0+1)=2.
10 = 22_4 and is divisible by prime(2+1)=5.
n = 1, 2, 3 are not divisible by prime(n+1) = 3, 5, 7; nor are 4=10_4, 5=11_4, and 7=13_4 divisible by prime(1+1) = 3; nor are 6=12_4, 8=20_4, 9=21_4 divisible by prime(2+1)=5.
		

Crossrefs

Programs

  • Mathematica
    Select[Range[0,2000],AllTrue[#/(Prime[#+1]&/@IntegerDigits[#,4]),IntegerQ]&] (* Harvey P. Dale, Mar 13 2025 *)
  • PARI
    is(n,b=4)=!for(i=1,#d=Set(digits(n,b)),n%prime(d[i]+1)&&return)

A256865 Numbers divisible by prime(d+1) for each digit d of their base-5 representation.

Original entry on oeis.org

0, 6, 10, 30, 50, 60, 110, 126, 150, 156, 168, 180, 210, 231, 250, 260, 300, 310, 378, 550, 630, 660, 726, 750, 756, 780, 810, 840, 900, 930, 1008, 1050, 1250, 1260, 1300, 1310, 1320, 1380, 1410, 1500, 1510, 1530, 1550, 1560, 1680, 1760, 1870, 1890, 1960, 2016, 2268, 2310, 2331, 2618, 2750, 2860, 3124, 3126, 3150, 3156, 3180
Offset: 1

Views

Author

M. F. Hasler, Apr 11 2015

Keywords

Comments

The base-5 variant of A256882 - A256884, A256866 - A256870 in bases 2, ..., 10.
A variant of A256875 where digits 0 are forbidden and divisibility by prime(d) is required.

Examples

			0 is divisible by prime(0+1)=2.
6 = 11_5 and is divisible by prime(1+1)=3.
10 = 20_5 and is divisible by prime(0+1)=2 and by prime(2+1)=5.
n = 1, 2, 3, 4 are not divisible by prime(n+1) = 3, 5, 7, 11. 5=10_5 is not divisible by prime(0+1)=2; 7=12_5 is not divisible by prime(2+1)=5, etc.
		

Crossrefs

Programs

  • PARI
    is(n,b=5)=!for(i=1,#d=Set(digits(n,b)),n%prime(d[i]+1)&&return)

A256870 Numbers divisible by prime(d+1) for each digit d of their base-10 representation.

Original entry on oeis.org

0, 20, 44, 111, 120, 171, 200, 210, 220, 290, 440, 520, 1020, 1110, 1113, 1200, 1710, 1914, 2000, 2010, 2020, 2030, 2100, 2145, 2200, 2220, 2310, 2420, 2900, 3220, 3381, 4004, 4048, 4400, 4444, 5200, 5525, 6120, 7220, 8280, 9338
Offset: 1

Views

Author

M. F. Hasler, Apr 11 2015

Keywords

Comments

A variant of A256786 where digits 0 are forbidden and divisibility by prime(d) is required.
See A256882 - A256884, A256866 - A256869 for the analog in bases 2, ..., 9.

Examples

			0 is divisible by prime(0+1)=2.
n = 1,...,9 are not divisible by prime(n+1) = 3, 5, ..., 29, respectively.
20 is divisible by prime(2+1)=5 and by prime(0+1)=2. The same is true for any other 2...20...0 =  2*10^k*(10^m-1)/9; k >= 1, m >= 0.
44 is divisible by prime(4+1)=11.
		

Crossrefs

Programs

  • PARI
    is(n,b=10)=!for(i=1,#d=Set(digits(n,b)),n%prime(d[i]+1)&&return)

A256882 Numbers divisible by prime(d+1) for each digit d of their base-2 representation.

Original entry on oeis.org

0, 3, 6, 12, 15, 18, 24, 30, 36, 42, 48, 54, 60, 63, 66, 72, 78, 84, 90, 96, 102, 108, 114, 120, 126, 132, 138, 144, 150, 156, 162, 168, 174, 180, 186, 192, 198, 204, 210, 216, 222, 228, 234, 240, 246, 252, 255, 258, 264, 270, 276, 282, 288, 294, 300, 306, 312, 318, 324, 330, 336, 342, 348, 354, 360, 366, 372, 378, 384, 390, 396, 402
Offset: 1

Views

Author

M. F. Hasler, Apr 11 2015

Keywords

Comments

Also, numbers divisible by 3 which are even or have no digit zero in their base-2 representation.
The base-2 variant of A256883 - A256884, A256865 - A256870 in bases 3,...,10.

Examples

			6 = 110_2 (in base 6), and 6 is divisible by prime(1+1)=3 and by prime(0+1) = 2.
9 = 101_2 is not in the sequence because it is odd but has a binary digit 0.
		

Crossrefs

Programs

  • PARI
    is(n,b=2)=!for(i=1,#d=Set(digits(n,b)),n%prime(d[i]+1)&&return)

A256866 Numbers divisible by prime(d+1) for each digit d of their base-6 representation.

Original entry on oeis.org

0, 6, 21, 36, 42, 126, 216, 222, 252, 258, 273, 300, 480, 510, 525, 560, 693, 735, 756, 770, 777, 880, 924, 1001, 1012, 1296, 1302, 1320, 1326, 1332, 1338, 1380, 1482, 1512, 1518, 1548, 1554, 1560, 1590, 1638, 1716, 1740, 1770, 1785, 1800, 1995, 2058, 2079, 2310, 2418
Offset: 1

Views

Author

M. F. Hasler, Apr 11 2015

Keywords

Comments

The base-6 variant of A256882 - A256884, A256866 - A256870 in bases 2, ..., 10.
A variant of A256876 where digits 0 are forbidden and divisibility by prime(d) is required.

Examples

			0 is divisible by prime(0+1)=2.
6 = 10_6 in base 6, and is divisible by prime(1+1)=3 and by prime(0+1)=2.
21 = 33_6, and is divisible by prime(3+1)=7.
n = 1, 2, 3, 4, 5 are not divisible by prime(n+1) = 3, 5, 7, 11, 13, respectively. 7=11_6, 8=12_6, 10=13_6, ... are not divisible by prime(1+1)=3; 9=12_7 is not divisible by prime(2+1)=5, etc.
		

Crossrefs

Programs

  • PARI
    is(n,b=6)=!for(i=1,#d=Set(digits(n,b)),n%prime(d[i]+1)&&return)

A256869 Numbers divisible by prime(d+1) for each digit d of their base-9 representation.

Original entry on oeis.org

0, 20, 84, 90, 180, 252, 273, 455, 510, 738, 756, 810, 816, 840, 900, 1224, 1275, 1460, 1470, 1620, 1640, 2090, 2185, 2268, 2450, 2541, 3080, 3289, 3553, 4199, 4590, 5434, 6570, 6642, 6660, 6804, 7290, 7326, 7344, 7380, 7395, 7470, 7560, 7866, 8100, 8160, 8190, 8778, 8841, 8925, 9282
Offset: 1

Views

Author

M. F. Hasler, Apr 11 2015

Keywords

Comments

The base-9 variant of A256882 - A256884, A256866 - A256870 in bases 2, ..., 10.
A variant of A256879 where digits 0 are forbidden and divisibility by prime(d) is required.
From Robert Israel, Aug 01 2019: (Start)
If n is in the sequence and is even, then 9*n is in the sequence.
If n is in the sequence and 9^k > n, then (9^k+1)*n is in the sequence.
All multiples of 223092870 are in the sequence.
(End)

Crossrefs

Programs

  • Maple
    P:= [seq(ithprime(i),i=1..9)]:
    filter:= proc(n) local L;
      L:= convert(convert(n,base,9),set);
      L:= map(t -> P[t+1],L);
      n mod convert(L,`*`) = 0
    end proc:
    select(filter, [$0..10000]); # Robert Israel, Aug 01 2019
  • PARI
    is(n,b=9)=!for(i=1,#d=Set(digits(n,b)),n%prime(d[i]+1)&&return)

Formula

a(n) ~ 223092870*n. - Robert Israel, Aug 01 2019

A256867 Numbers divisible by prime(d+1) for each digit d of their base-7 representation.

Original entry on oeis.org

0, 15, 57, 100, 168, 182, 396, 450, 624, 700, 750, 800, 840, 1050, 1176, 1190, 1274, 1485, 1540, 1716, 2520, 2652, 2760, 2772, 2814, 2850, 2898, 2970, 3150, 3486, 3570, 3861, 4173, 4368, 4488, 4860, 4900, 4940, 4970, 5160, 5250, 5490, 5595, 5600, 5880, 5950, 6435, 6630, 7224, 7350, 7560, 7602, 7910, 8050, 8232, 8330
Offset: 1

Views

Author

M. F. Hasler, Apr 11 2015

Keywords

Comments

The base-7 variant of A256882 - A256884, A256865 - A256870 in bases 2, ..., 10.
A variant of A256877 where digits 0 are forbidden and divisibility by prime(d) is required.

Crossrefs

Programs

  • Mathematica
    Select[Range[0,9000],AllTrue[#/Prime[IntegerDigits[#,7]+1],IntegerQ]&] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Sep 17 2020 *)
  • PARI
    is(n,b=7)=!for(i=1,#d=Set(digits(n,b)),n%prime(d[i]+1)&&return)

A256868 Numbers divisible by prime(d+1) for each digit d of their base-8 representation.

Original entry on oeis.org

0, 9, 33, 57, 72, 130, 210, 264, 456, 570, 576, 585, 660, 969, 1040, 1050, 1170, 1365, 1540, 1680, 1995, 2112, 2145, 2508, 2600, 2730, 2860, 2925, 3366, 3648, 3705, 4047, 4104, 4170, 4356, 4488, 4560, 4608, 4620, 4680, 4683, 4809, 4998, 5130, 5250, 5265, 5280, 6825, 7752, 8210, 8320, 8400, 8850, 9240, 9350, 9360, 9555
Offset: 1

Views

Author

M. F. Hasler, Apr 11 2015

Keywords

Comments

The base-8 variant of A256882 - A256884, A256866 - A256870 in bases 2, ..., 10.
A variant of A256878 where digits 0 are forbidden and divisibility by prime(d) is required.

Crossrefs

Programs

  • Mathematica
    Select[Range[0,10000],And@@Divisible[#,Prime[IntegerDigits[#,8]+1]]&] (* Harvey P. Dale, May 06 2015 *)
  • PARI
    is(n,b=8)=!for(i=1,#d=Set(digits(n,b)),n%prime(d[i]+1)&&return)
Showing 1-8 of 8 results.