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.

A200520 Least m>0 such that n = y^2 - 10^x (mod m) has no solution, or 0 if no such m exists.

Original entry on oeis.org

0, 3, 5, 0, 3, 9, 0, 3, 0, 11, 3, 9, 5, 3, 9, 0, 3, 5, 11, 3, 9, 0, 3, 9, 0, 3, 0, 5, 3, 9, 16, 3, 5, 20, 3, 0, 1001, 3, 9, 0, 3, 9, 5, 3, 0, 56, 3, 5, 0, 3, 9, 11, 3, 11, 0, 3, 9, 5, 3, 9, 112, 3, 5, 0, 3, 9, 16, 3, 9, 0, 3, 0, 5, 3, 9, 11, 3, 5, 16, 3, 0, 3367
Offset: 0

Views

Author

M. F. Hasler, Nov 18 2011

Keywords

Comments

To prove that an integer n is in A051212, it is sufficient to find integers x,y such that y^2 - 10^x = n. In that case, a(n)=0. To prove that n is *not* in A051212, it is sufficient to find a modulus m for which the (finite) set of all possible values of 10^x and y^2 allows us to deduce that y^2 - 10^x can never equal n. The present sequence lists the smallest such m>0, if it exists.

Examples

			See A200512 for motivation and detailed examples.
		

Crossrefs

Programs

  • PARI
    A200520(n,b=10,p=3)={ my( x=0, qr, bx, seen ); for( m=3,9e9, while( x^p < m, issquare(b^x+n) & return(0); x++); qr=vecsort(vector(m,y,y^2-n)%m,,8); seen=0; bx=1; until( bittest(seen+=1<bx & break; next(3))); return(m))}

A200513 Least m>0 such that n = y^2 - 3^x (mod m) has no solution, or 0 if no such m exists.

Original entry on oeis.org

0, 0, 8, 0, 8, 9, 0, 0, 0, 0, 8, 9, 8, 0, 9, 0, 0, 12, 8, 0, 8, 28, 0, 9, 0, 20, 8, 0, 8, 9, 20, 80, 9, 0, 8, 0, 8, 0, 9, 63, 0, 9, 8, 80, 8, 20, 0, 9, 0, 28, 8, 63, 8, 12, 0, 0, 9, 36, 8, 9, 8, 0, 12, 0, 532, 9, 8, 80, 8, 108, 20, 15, 0, 0, 8, 63, 8, 9, 0
Offset: 0

Views

Author

M. F. Hasler, Nov 18 2011

Keywords

Comments

To prove that an integer n is in A051205, it is sufficient to find integers x,y such that y^2 - 3^x = n. In that case, a(n)=0. To prove that n is *not* in A051205, it is sufficient to find a modulus m for which the (finite) set of all possible values of 3^x and y^2 (mod m) allows us to deduce that y^2 - 3^x can never equal n. The present sequence lists the smallest such m>0, if it exists.

Examples

			See A200512.
		

Crossrefs

Programs

  • PARI
    A200513(n,b=3,p=3)={ my( x=0, qr, bx, seen ); for( m=3,9e9, while( x^p < m, issquare(b^x+n) & return(0); x++); qr=vecsort(vector(m,y,y^2-n)%m,,8); seen=0; bx=1; until( bittest(seen+=1<bx & break; next(3))); return(m))}

A200514 Least m>0 such that n = y^2 - 4^x (mod m) has no solution, or 0 if no such m exists.

Original entry on oeis.org

0, 3, 4, 0, 3, 0, 4, 3, 0, 0, 3, 16, 0, 3, 4, 0, 3, 0, 4, 3, 0, 0, 3, 16, 0, 3, 4, 16, 3, 40, 4, 3, 0, 0, 3, 0, 0, 3, 4, 16, 3, 63, 4, 3, 63, 0, 3, 20, 0, 3, 4, 20, 3, 40, 4, 3, 80, 0, 3, 16, 0, 3, 4, 0, 3, 0, 4, 3, 0, 40, 3, 16, 80, 3, 4, 16, 3, 0, 4, 3, 0
Offset: 0

Views

Author

M. F. Hasler, Nov 18 2011

Keywords

Comments

To prove that an integer n is in A051206, it is sufficient to find integers x,y such that y^2 - 4^x=n. In that case, a(n)=0. To prove that n is *not* in A051206, it is sufficient to find a modulus m for which the (finite) set of all possible values of 4^x and y^2 (mod m) allows us to deduce that y^2 - 4^x can never equal n. The present sequence lists the smallest such m>0, if it exists.

Examples

			See A200512.
		

Crossrefs

Programs

  • PARI
    A200514(n,b=4,p=3)={ my( x=0, qr, bx, seen ); for( m=3,9e9, while( x^p < m, issquare(b^x+n) & return(0); x++); qr=vecsort(vector(m,y,y^2-n)%m,,8); seen=0; bx=1; until( bittest(seen+=1<bx & break; next(3))); return(m))}

A200515 Least m>0 such that n = y^2 - 5^x (mod m) has no solution, or 0 if no such m exists.

Original entry on oeis.org

0, 4, 4, 0, 0, 4, 4, 5, 0, 4, 4, 0, 5, 4, 4, 0, 24, 4, 4, 0, 0, 4, 4, 35, 0, 4, 4, 5, 15, 4, 4, 0, 5, 4, 4, 0, 24, 4, 4, 0, 24, 4, 4, 15, 0, 4, 4, 5, 0, 4, 4, 0, 5, 4, 4, 39, 0, 4, 4, 0, 24, 4, 4, 0, 24, 4, 4, 5, 35, 4, 4, 0, 5, 4, 4, 0, 0, 4, 4, 63, 0, 4, 4
Offset: 0

Views

Author

M. F. Hasler, Nov 18 2011

Keywords

Comments

To prove that an integer n is in A051207, it is sufficient to find integers x,y such that y^2 - 5^x = n. In that case, a(n)=0. To prove that n is *not* in A051207, it is sufficient to find a modulus m for which the (finite) set of all possible values of 5^x and y^2 (mod m) allows us to deduce that y^2 - 5^x can never equal n. The present sequence lists the smallest such m>0, if it exists.

Examples

			See A200512 for motivation and detailed examples.
		

Crossrefs

Programs

  • PARI
    A200515(n,b=5,p=3)={ my( x=0, qr, bx, seen ); for( m=3,9e9, while( x^p < m, issquare(b^x+n) & return(0); x++); qr=vecsort(vector(m,y,y^2-n)%m,,8); seen=0; bx=1; until( bittest(seen+=1<bx & break; next(3))); return(m))}

Formula

A200515(A051207(k))=0 for all k in N.
A200515(1+4k)=A200515(2+4k)=4 for all k>=0.

A200516 Least m>0 such that n = y^2 - 6^x (mod m) has no solution, or 0 if no such m exists.

Original entry on oeis.org

0, 5, 5, 0, 7, 9, 5, 5, 0, 0, 0, 5, 5, 0, 9, 0, 5, 5, 7, 0, 9, 5, 5, 9, 0, 7, 5, 5, 0, 9, 0, 5, 5, 36, 16, 0, 5, 5, 9, 7, 0, 5, 5, 0, 21, 0, 5, 5, 0, 43, 9, 5, 5, 7, 16, 16, 5, 5, 0, 9, 7, 5, 5, 0, 0, 9, 5, 5, 9, 36, 16, 5, 5, 0, 7, 0, 5, 5, 32, 24, 0, 5, 5
Offset: 0

Views

Author

M. F. Hasler, Nov 18 2011

Keywords

Comments

To prove that an integer n is in A051208, it is sufficient to find integers x,y such that y^2 - 6^x = n. In that case, a(n)=0. To prove that n is *not* in A051208, it is sufficient to find a modulus m for which the (finite) set of all possible values of 6^x and y^2 (mod m) allows us to deduce that y^2 - 6^x can never equal n. The present sequence lists the smallest such m>0, if it exists.

Examples

			See A200512 for motivation and detailed examples.
		

Crossrefs

Programs

  • PARI
    A200516(n,b=6,p=3)={ my( x=0, qr, bx, seen ); for( m=3,9e9, while( x^p < m, issquare(b^x+n) & return(0); x++); qr=vecsort(vector(m,y,y^2-n)%m,,8); seen=0; bx=1; until( bittest(seen+=1<bx & break; next(3))); return(m))}

A200517 Least m>0 such that n = y^2 - 7^x (mod m) has no solution, or 0 if no such m exists.

Original entry on oeis.org

0, 3, 0, 0, 3, 7, 8, 3, 0, 0, 3, 16, 7, 3, 8, 0, 3, 16, 0, 3, 8, 16, 3, 16, 0, 3, 7, 16, 3, 0, 8, 3, 0, 7, 3, 0, 8, 3, 8, 16, 3, 28, 0, 3, 8, 19, 3, 7, 0, 3, 20, 0, 3, 16, 7, 3, 100, 0, 3, 16, 8, 3, 8, 0, 3, 16, 28, 3, 7, 16, 3, 16, 0, 3, 0, 7, 3, 19, 8, 3
Offset: 0

Views

Author

M. F. Hasler, Nov 18 2011

Keywords

Comments

To prove that an integer n is in A051209, it is sufficient to find integers x,y such that y^2 - 7^x = n. In that case, a(n)=0. To prove that n is *not* in A051209, it is sufficient to find a modulus m for which the (finite) set of all possible values of 7^x and y^2 allows us to deduce that y^2-7^x can never equal n. The present sequence lists the smallest such m>0, if it exists.

Examples

			See A200512 for motivation and detailed examples.
		

Crossrefs

Programs

  • PARI
    A200517(n,b=7,p=3)={ my( x=0, qr, bx, seen ); for( m=3,9e9, while( x^p < m, issquare(b^x+n) & return(0); x++); qr=vecsort(vector(m,y,y^2-n)%m,,8); seen=0; bx=1; until( bittest(seen+=1<bx & break; next(3))); return(m))}

A200518 Least m>0 such that n = y^2-8^x (mod m) has no solution, or 0 if no such m exists.

Original entry on oeis.org

0, 0, 4, 0, 7, 7, 4, 9, 0, 7, 4, 7, 7, 8, 4, 0, 7, 0, 4, 7, 32, 8, 4, 7, 0, 7, 4, 16, 0, 8, 4, 9, 7, 7, 4, 0, 0, 7, 4, 7, 7, 0, 4, 9, 7, 8, 4, 7, 0, 9, 4, 7, 9, 7, 4, 12, 0, 0, 4, 16, 7, 7, 4, 0, 0, 7, 4, 7, 7, 8, 4, 16, 7, 0, 4, 7, 9, 8, 4, 7, 0, 7, 4, 32
Offset: 0

Views

Author

M. F. Hasler, Nov 18 2011

Keywords

Comments

If a(n)>0, this proves that n cannot be a member of A051210, i.e., cannot be written as y^2-8^x. To prove that an integer n is in A051210, it is sufficient to find integers x,y such that y^2-8^x=n. In that case, a(n)=0.

Examples

			See A200512 for motivation and detailed examples.
		

Crossrefs

Programs

  • PARI
    A200518(n,b=8,p=3)={ my( x=0, qr, bx, seen ); for( m=3,9e9, while( x^p < m, issquare(b^x+n) & return(0); x++); qr=vecsort(vector(m,y,y^2-n)%m,,8); seen=0; bx=1; until( bittest(seen+=1<bx & break; next(3))); return(m))}

A200519 Least m>0 such that n = y^2 - 9^x (mod m) has no solution, or 0 if no such m exists.

Original entry on oeis.org

0, 4, 4, 0, 8, 4, 4, 0, 0, 4, 4, 9, 8, 4, 4, 0, 0, 4, 4, 0, 8, 4, 4, 9, 0, 4, 4, 0, 8, 4, 4, 80, 9, 4, 4, 0, 8, 4, 4, 63, 0, 4, 4, 80, 8, 4, 4, 9, 0, 4, 4, 45, 8, 4, 4, 0, 9, 4, 4, 9, 8, 4, 4, 0, 133, 4, 4, 80, 8, 4, 4, 15, 0, 4, 4, 63, 8, 4, 4
Offset: 0

Views

Author

M. F. Hasler, Nov 18 2011

Keywords

Comments

To prove that an integer n is in A051211, it is sufficient to find integers x,y such that y^2 - 9^x = n. In that case, a(n)=0. To prove that n is *not* in A051211, it is sufficient to find a modulus m for which the (finite) set of all possible values of 9^x and y^2 (mod m) allows us to deduce that y^2 - 9^x can never equal n. The present sequence lists the smallest such m>0, if it exists.

Examples

			See A200512 for motivation and detailed examples.
		

Crossrefs

Programs

  • PARI
    A200519(n,b=9,p=3)={ my( x=0, qr, bx, seen ); for( m=3,9e9, while( x^p < m, issquare(b^x+n) & return(0); x++); qr=vecsort(vector(m,y,y^2-n)%m,,8); seen=0; bx=1; until( bittest(seen+=1<bx & break; next(3))); return(m))}
Showing 1-8 of 8 results.