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.

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A036956 Primes containing only digits from the set (0,1,2,3,4).

Original entry on oeis.org

2, 3, 11, 13, 23, 31, 41, 43, 101, 103, 113, 131, 211, 223, 233, 241, 311, 313, 331, 401, 421, 431, 433, 443, 1013, 1021, 1031, 1033, 1103, 1123, 1201, 1213, 1223, 1231, 1301, 1303, 1321, 1423, 1433, 2003, 2011, 2111, 2113, 2131, 2141, 2143, 2203, 2213
Offset: 1

Views

Author

Patrick De Geest, Jan 04 1999

Keywords

Crossrefs

Subsequence of A036958.

Extensions

Offet 1 from Michel Marcus, Oct 10 2019

A235479 Primes whose base-2 representation also is the base-9 representation of a prime.

Original entry on oeis.org

11, 13, 19, 41, 79, 109, 137, 151, 167, 191, 193, 199, 227, 239, 271, 307, 313, 421, 431, 433, 457, 487, 491, 521, 563, 613, 617, 659, 677, 709, 727, 757, 929, 947, 1009, 1033, 1051, 1249, 1483, 1693, 1697, 1709, 1721, 1831, 1951, 1979, 1987, 1993
Offset: 1

Views

Author

M. F. Hasler, Jan 12 2014

Keywords

Comments

This sequence is part of a two-dimensional array of sequences, given in the LINK, based on this same idea for any two different bases b, c > 1. Sequence A235265 and A235266 are the most elementary ones in this list. Sequences A089971, A089981 and A090707 through A090721, and sequences A065720 - A065727, follow the same idea with one base equal to 10.
For further motivation and cross-references, see sequence A235265 which is the main entry for this whole family of sequences.
A subsequence of A027697, A050150, A062090 and A176620.

Examples

			11 = 1011_2 and 1011_9 = 6571 are both prime, so 11 is a term.
		

Crossrefs

Cf. A235466A077723, A235266, A152079, A235475 - A235478, A065720A036952, A065721 - A065727, A089971A020449, A089981, A090707 - A091924, A235394, A235395, A235461 - A235482. See the LINK for further cross-references.

Programs

  • PARI
    is(p,b=9)=isprime(vector(#d=binary(p),i,b^(#d-i))*d~)&&isprime(p)

A267490 Primes whose base-8 representation is a perfect square in base 10.

Original entry on oeis.org

149, 241, 661, 1409, 2593, 3733, 6257, 7793, 15313, 23189, 25601, 26113, 30497, 34337, 44053, 49057, 78577, 92821, 95009, 108529, 115861, 132757, 162257, 178417, 183377, 223381, 235541, 242197, 266261, 327317, 345749, 426389, 525461, 693397, 719893, 729713, 805397, 814081, 903841
Offset: 1

Views

Author

Christopher Cormier, Jan 16 2016

Keywords

Comments

Subsequence of primes in A267768. - M. F. Hasler, Jan 20 2016

Examples

			a(1) = 149 because 149 is 225 in base 8, and 225 is 15^2 in base 10.
		

Crossrefs

For primes which are primes in other bases, see A235265, A235266, A152079, A235461 - A235482, A065720A036952, A065721 - A065727, A235394, A235395, A089971A020449, A089981, A090707 - A091924.

Programs

  • Magma
    [n:n in PrimesUpTo(1000000)| IsSquare(Seqint(Intseq(n,8)))]; // Marius A. Burtea, Jun 30 2019
  • Mathematica
    Select[Prime@ Range[10^5], IntegerQ@ Sqrt@ FromDigits@ IntegerDigits[#, 8] &] (* Michael De Vlieger, Jan 16 2016 *)
  • PARI
    listp(nn) = {forprime(p=1, nn, d = digits(p, 8); pd = Pol(d); if (issquare(subst(pd, x, 10)), print1(p, ", ")););} \\ Michel Marcus, Jan 16 2016
    
  • PARI
    is(n,b=8,c=10)={issquare(subst(Pol(digits(n,b)),x,c))&&isprime(n)} \\ M. F. Hasler, Jan 20 2016
    
  • Python
    from sympy import isprime
    A267490_list = [int(s,8) for s in (str(i**2) for i in range(10**6)) if max(s) < '8' and isprime(int(s,8))] # Chai Wah Wu, Jan 20 2016
    

A036954 Primes with digits in {0,1,2} taken as base 3 and converted to base 10.

Original entry on oeis.org

2, 4, 10, 22, 34, 46, 58, 67, 79, 94, 103, 139, 145, 157, 166, 169, 172, 181, 190, 193, 199, 205, 211, 214, 229, 277, 283, 295, 298, 307, 313, 349, 367, 373, 391, 394, 409, 421, 433, 439, 463, 466, 478, 505, 517, 523, 529, 535, 541, 547, 556, 559, 571, 577
Offset: 1

Views

Author

Patrick De Geest, Jan 04 1999

Keywords

Comments

Equivalently: terms of A036953 read in base 3 (and written in base 10). - M. F. Hasler, Jul 25 2015
Equivalently, k such that A007089(k), read literally as a decimal number, is a prime. - N. J. A. Sloane, Feb 17 2023

Examples

			a(n) = 313 is 102121{3}, and 102121{10} is prime.
		

Crossrefs

Indices of primes in A007089.

Programs

  • Mathematica
    FromDigits[#,3]&/@Select[Tuples[{0,1,2},6],PrimeQ[FromDigits[#]]&] (* Harvey P. Dale, Mar 27 2021 *)
  • PARI
    is(n)=(n%3==1||n==2)&&isprime((n=digits(n,3))*vectorv(#n,i,10^(#n-i))) \\ M. F. Hasler, Jul 25 2015

Formula

a(n) == 1 (mod 3) for all n > 1. - M. F. Hasler, Jul 25 2015

Extensions

Offset corrected to 1 and minor edits by M. F. Hasler, Jul 25 2015

A036958 Primes containing only digits from the set (0,1,2,3,4,5).

Original entry on oeis.org

2, 3, 5, 11, 13, 23, 31, 41, 43, 53, 101, 103, 113, 131, 151, 211, 223, 233, 241, 251, 311, 313, 331, 353, 401, 421, 431, 433, 443, 503, 521, 523, 541, 1013, 1021, 1031, 1033, 1051, 1103, 1123, 1151, 1153, 1201, 1213, 1223, 1231, 1301, 1303, 1321
Offset: 1

Views

Author

Patrick De Geest, Jan 04 1999

Keywords

Crossrefs

Subsequence of A036960.

Programs

  • Mathematica
    Select[Prime[Range[220]],Max[IntegerDigits[#]]<6&] (* Harvey P. Dale, Sep 23 2011 *)

Extensions

Offset 1 from Michel Marcus, Oct 10 2019

A235474 Primes whose base-4 representation is also the base-5 representation of a prime.

Original entry on oeis.org

2, 3, 11, 29, 31, 41, 101, 109, 139, 149, 151, 181, 199, 229, 239, 251, 269, 271, 281, 389, 409, 491, 509, 541, 547, 661, 751, 887, 911, 947, 991, 1021, 1051, 1061, 1069, 1091, 1151, 1279, 1289, 1381, 1409, 1471, 1549, 1709, 1759, 1801, 1999
Offset: 1

Views

Author

M. F. Hasler, Jan 12 2014

Keywords

Comments

This sequence is part of a two-dimensional array of sequences, given in the LINK, based on this same idea for any two different bases b, c > 1. Sequence A235265 and A235266 are the most elementary ones in this list. Sequences A089971, A089981 and A090707 through A090721, and sequences A065720 - A065727, follow the same idea with one base equal to 10.
For further motivation and cross-references, see sequence A235265 which is the main entry for this whole family of sequences.

Examples

			11 = 23_4 and 23_5 = 13 are both prime, so 11 is a term.
		

Crossrefs

Cf. A235266, A235473, A152079, A235475 - A235479, A065720A036952, A065721 - A065727, A235394, A235395, A089971A020449, A089981, A090707 - A091924, A235461 - A235482. See the LINK for further cross-references.

Programs

  • Mathematica
    Select[Prime[Range[400]],PrimeQ[FromDigits[IntegerDigits[#,4],5]]&] (* Harvey P. Dale, Dec 31 2017 *)
  • PARI
    is(p,b=5,c=4)=isprime(vector(#d=digits(p,c),i,b^(#d-i))*d~)&&isprime(p) \\ Note: This code is only valid for b > c.

A235477 Primes whose base-2 representation also is the base-7 representation of a prime.

Original entry on oeis.org

2, 31, 47, 59, 103, 107, 173, 179, 181, 199, 211, 227, 229, 233, 367, 409, 443, 463, 487, 701, 743, 757, 823, 827, 877, 911, 919, 967, 1009, 1123, 1163, 1291, 1321, 1367, 1373, 1447, 1493, 1571, 1583, 1597, 1609, 1627, 1657, 1669, 1721, 1831, 1933, 1987
Offset: 1

Views

Author

M. F. Hasler, Jan 12 2014

Keywords

Comments

This sequence is part of a two-dimensional array of sequences, given in the LINK, based on this same idea for any two different bases b, c > 1. Sequence A235265 and A235266 are the most elementary ones in this list. Sequences A089971, A089981 and A090707 through A090721, and sequences A065720 - A065727, follow the same idea with one base equal to 10.
For further motivation and cross-references, see sequence A235265 which is the main entry for this whole family of sequences.
A subsequence of A027697, A015919, A197636 (conjectural).

Examples

			31 = 11111_2 and 11111_7 = 2801 are both prime, so 31 is a term.
		

Crossrefs

Cf. A235464A077721, A235475, A152079, A235266, A065720A036952, A065721 - A065727, A089971A020449, A089981, A090707 - A091924, A235394, A235395, A235461 - A235482. See the LINK for further cross-references.

Programs

  • Mathematica
    Select[Prime[Range[300]],PrimeQ[FromDigits[IntegerDigits[#,2],7]]&] (* Harvey P. Dale, May 08 2021 *)
  • PARI
    is(p,b=7)=isprime(vector(#d=binary(p),i,b^(#d-i))*d~)&&isprime(p)

A036960 Primes containing only digits from the set (0,1,2,3,4,5,6).

Original entry on oeis.org

2, 3, 5, 11, 13, 23, 31, 41, 43, 53, 61, 101, 103, 113, 131, 151, 163, 211, 223, 233, 241, 251, 263, 311, 313, 331, 353, 401, 421, 431, 433, 443, 461, 463, 503, 521, 523, 541, 563, 601, 613, 631, 641, 643, 653, 661, 1013, 1021, 1031, 1033, 1051, 1061, 1063
Offset: 1

Views

Author

Patrick De Geest, Jan 04 1999

Keywords

Crossrefs

Subsequence of A036962.

Programs

  • Mathematica
    Select[Prime[Range[200]],Max[IntegerDigits[#]]<7&] (* Harvey P. Dale, Feb 08 2019 *)

Extensions

Offset 1 from Michel Marcus, Oct 10 2019

A231474 Primes whose base-3 representation is also the base-5 representation of a prime.

Original entry on oeis.org

2, 3, 5, 7, 13, 17, 29, 31, 37, 41, 59, 67, 79, 97, 101, 109, 113, 137, 139, 149, 151, 173, 181, 193, 223, 229, 251, 269, 271, 293, 311, 331, 353, 367, 373, 379, 383, 389, 397, 401, 457, 467, 491, 503, 617, 631, 641, 647, 653, 673, 701, 773, 787, 797, 809, 829, 853, 857, 911, 929, 953, 977
Offset: 1

Views

Author

M. F. Hasler, Jan 12 2014

Keywords

Comments

This sequence is part of a two-dimensional array of sequences, given in the LINK, based on this same idea for any two different bases b, c > 1. Sequence A235265 and A235266 are the most elementary ones in this list. Sequences A089971, A089981 and A090707 through A090721, and sequences A065720 - A065727, follow the same idea with one base equal to 10.

Examples

			7 = 21_3 and 21_5 = 11 are both prime, so 7 is a term.
		

Crossrefs

Cf. A235265, A235266, A235473, A152079, A235461 - A235482, A065720A036952, A065721 - A065727, A235394, A235395, A089971A020449, A089981, A090707 - A091924. See the LINK for further cross-references.

Programs

  • Mathematica
    Select[Prime@ Range@ 500, PrimeQ@ FromDigits[ IntegerDigits[#, 3], 5] &] (* Giovanni Resta, Sep 12 2019 *)
  • PARI
    is(p,b=5,c=3)=isprime(vector(#d=digits(p,c),i,b^(#d-i))*d~)&&isprime(p) \\ Note: This code is only valid for b > c.

A231477 Primes whose base-3 representation is also the base-7 representation of a prime.

Original entry on oeis.org

2, 3, 23, 41, 47, 53, 61, 67, 71, 89, 113, 127, 131, 137, 191, 193, 223, 251, 269, 283, 293, 311, 353, 397, 409, 421, 443, 463, 491, 503, 509, 541, 569, 601, 613, 701, 773, 787, 983, 1013, 1031, 1091, 1117, 1213, 1223, 1429, 1499, 1543, 1549, 1579, 1619, 1621, 1697, 1699, 1733, 1873, 1933, 1949, 1951, 1973
Offset: 1

Views

Author

M. F. Hasler, Jan 12 2014

Keywords

Comments

This sequence is part of a two-dimensional array of sequences, given in the LINK, based on this same idea for any two different bases b, c > 1. Sequence A235265 and A235266 are the most elementary ones in this list. Sequences A089971, A089981 and A090707 through A090721, and sequences A065720 - A065727, follow the same idea with one base equal to 10.

Examples

			23 = 212_3 and 212_7 = 107 are both prime, so 23 is a term.
		

Crossrefs

Cf. A235470, A235265, A235266, A152079, A235461 - A235482, A065720A036952, A065721 - A065727, A235394, A235395, A089971A020449, A089981, A090707 - A091924. See the LINK for further cross-references.

Programs

  • Mathematica
    Select[Prime@Range@500, PrimeQ@FromDigits[IntegerDigits[#, 3], 7] &] (* Giovanni Resta, Sep 12 2019 *)
  • PARI
    is(p,b=7,c=3)=isprime(vector(#d=digits(p,c),i,b^(#d-i))*d~)&&isprime(p) \\ Note: This code is only valid for b > c.
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