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.

A116133 Numbers k such that k concatenated with k-4 gives the product of two numbers which differ by 9.

Original entry on oeis.org

64, 1876, 3214, 8776, 17227120144584448354, 19391087990479091186, 21557280540171744040, 23970390649400564404, 26051259424903756364, 28697643366269876506, 31320461807899711990, 34215988012600009664
Offset: 1

Views

Author

Giovanni Resta, Feb 06 2006

Keywords

Comments

Also numbers k such that k concatenated with k+4 gives the product of two numbers which differ by 7.
Since k*(10^j+1) + 4 = m*(m+7) iff k*(10^j+1) - 4 = m*(m+7) - 8 = (m-1)*(m+8) = M*(M+9) this is trivially the same sequence. - N. J. A. Sloane, Apr 11 2007

Examples

			8776//8772 = 9364 * 9373, where // denotes concatenation. Also 8776//8780 = 9365 * 9372.

Crossrefs

Cf. A116132, A116140, A116264.
Cf. A116180, A116187, A116189, A116195, A116319.

Extensions

Edited by N. J. A. Sloane, Apr 11 2007

A116147 Numbers k such that k concatenated with k-2 gives the product of two numbers which differ by 9.

Original entry on oeis.org

4962, 237412345332, 262912791034, 468307643502
Offset: 1

Views

Author

Giovanni Resta, Feb 06 2006

Keywords

Comments

Also, numbers k such that k concatenated with k+6 gives the product of two numbers which differ by 7.

Examples

			4962//4960 = 7040 * 7049, where // denotes concatenation.

Crossrefs

Cf. A116140, A116146, A116153, A116278.
Cf. A116195, A116200, A116202, A116209, A116332.

Extensions

Edited by N. J. A. Sloane at the suggestion of Eric Desbiaux, Mar 23 2008

A116139 Numbers k such that k concatenated with k-3 gives the product of two numbers which differ by 8.

Original entry on oeis.org

43, 20440836, 30017751, 61336887, 52400871197755334426147587, 53651708763838760619655612, 56652002793835820319625612, 57952296063256269823192087, 17684775866714240650923831481623
Offset: 1

Views

Author

Giovanni Resta, Feb 06 2006

Keywords

Examples

			61336887//61336884 = 78317866 * 78317874, where // denotes concatenation.

Crossrefs

Cf. A116126, A116205, A116140, A116146, A116270.

A116271 n times n+9 gives the concatenation of two numbers m and m-3.

Original entry on oeis.org

4, 8600, 9422, 35440, 64552, 73643, 4851411, 5148581, 8784945, 726216462984, 753613723258, 791909893641, 819307153915, 3654754464602947512, 4527063717215234298, 5472936282784765694, 6345245535397052480
Offset: 1

Views

Author

Giovanni Resta, Feb 06 2006

Keywords

Examples

			8784945 * 8784954 = 7717533//7717530, where // denotes
concatenation.

Crossrefs

Cf. A116140, A116264, A116270, A116278.
Showing 1-4 of 4 results.

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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