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 1-5 of 5 results.

A116180 Numbers k such that k concatenated with k+3 gives the product of two numbers which differ by 7.

Original entry on oeis.org

7137, 7767, 47783068991048776635, 48797525371338932241, 55658688122404752991, 56753136503494828605, 85555875266989354735, 86911515887391841491, 95992713077544748491, 97428345698747155255
Offset: 1

Views

Author

Giovanni Resta, Feb 06 2006

Keywords

Comments

Also numbers k such that k concatenated with k-5 gives the product of two numbers which differ by 9.
Also numbers k such that k concatenated with k+9 gives the product of two numbers which differ by 5.

Examples

			7767//7770 = 8810 * 8817, where // denotes concatenation.
7767//7762 = 8809 * 8818.
7767//7776 = 8811 * 8816.

Crossrefs

Cf. A116167, A116179, A116181, A116133, A116311.
Cf. A116114, A116126, A116133, A116258.
Cf. A116207, A116187, A116174, A116351.

Extensions

Edited by N. J. A. Sloane, Apr 12 2007

A116173 Numbers k such that k concatenated with k+2 gives the product of two numbers which differ by 6.

Original entry on oeis.org

6752089, 6448802889351008245, 18894512461523256139943105859903480218905, 31958875438439894736354375209245786214798
Offset: 1

Views

Author

Giovanni Resta, Feb 06 2006

Keywords

Comments

Also numbers k such that k concatenated with k+7 gives the product of two numbers which differ by 4.
If k+2 and k-5 have the same number of digits, the k is also in A116126, because k//k+2 = 10^d*k + k + 2 = m*(m+6) then implies a representation k//k-5 = 10^d*k + k - 5 = m*(m+6)-7 = (m-1)*(m+7). - R. J. Mathar, Aug 10 2008

Examples

			6752089//6752091 = 8217107 * 8217113, where // denotes concatenation.
6752089//6752096 = 8217108 * 8217112.

Crossrefs

Cf. A116159, A116172, A116174, A116187, A116304.
Cf. A115430, A116205, A116207, A116187, A116337.

Extensions

Edited by N. J. A. Sloane, Apr 12 2007

A116200 Numbers k such that k concatenated with k+6 gives the product of two numbers which differ by 5.

Original entry on oeis.org

210, 294, 5880, 52888, 127044, 414180, 8264470, 12456750, 41868508, 112670544, 441341880, 468144040, 669421494, 702338994, 715976338, 750005718, 960645294, 1491030294, 3768258010, 4783279044, 8505429358, 17105045530
Offset: 1

Views

Author

Giovanni Resta, Feb 06 2006

Keywords

Crossrefs

Cf. A116193, A116172, A116147, A116207, A116331.

A116208 Numbers k such that k concatenated with k+7 gives the product of two numbers which differ by 6.

Original entry on oeis.org

145, 384, 505, 820, 7680, 20665, 29748, 480340, 6694209, 77854665, 107541513, 109342209, 132231408, 174990384, 183673473, 213017748, 289940833, 326530608, 338353345, 404958673, 448003540, 451671060, 478271265
Offset: 1

Views

Author

Giovanni Resta, Feb 06 2006

Keywords

Crossrefs

Cf. A116194, A116207, A116209, A116168, A116339.

A116338 n times n+5 gives the concatenation of two numbers m and m+7.

Original entry on oeis.org

700, 777, 791, 868, 42338, 57658, 96884, 44121667, 55878329, 85298138, 36680703009575609347721358494, 63319296990424390652278641502, 69346342454876071597336150482, 81501115172242572470460459684
Offset: 1

Views

Author

Giovanni Resta, Feb 06 2006

Keywords

Examples

			85298138 * 85298143 = 72757727//72757734, where // denotes
concatenation.

Crossrefs

Cf. A116207, A116331, A116337, A116339, A116351.
Showing 1-5 of 5 results.

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

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