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 1-6 of 6 results.

A116112 Numbers k such that k concatenated with k-7 gives the product of two numbers which differ by 7.

Original entry on oeis.org

17, 35, 10408517, 45884051, 62918301, 1116290522645838319925, 1491109615209578451401, 2254276950187476704727, 2758431647767103545151, 3768131911733856383477, 4434103687048263321737, 5230580700713956424051
Offset: 1

Views

Author

Giovanni Resta, Feb 06 2006

Keywords

Comments

Also numbers k such that k concatenated with k-1 gives the product of two numbers which differ by 5.
Also numbers k such that k concatenated with k+3 gives the product of two numbers which differ by 3.
Also numbers k such that k concatenated with k+5 gives the product of two numbers which differ by 1.

Examples

			62918301//62918300 = 79321055 * 79321060, where // denotes concatenation.
62918301//62918304 = 79321056 * 79321059.
62918301//62918306 = 79321057 * 79321058.

Crossrefs

Cf. A116107, A115426, A116113, A116119, A116243.
Cf. A116163, A115429, A116158, A116281.
Cf. A116171, A116177, A116179, A116185, A116309, A115430, A116322.

Extensions

Edited by N. J. A. Sloane, Apr 15 2007

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

A116172 Numbers k such that k concatenated with k+2 gives the product of two numbers which differ by 5.

Original entry on oeis.org

2, 74, 59264, 510782, 906902, 81790664, 92776472, 10876856041862, 11796926254874, 18332259798794, 18388650720624, 32624670587648, 32699883214248, 43103618706398, 44916698243804, 66132258426302
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 3.
Also numbers k such that k concatenated with k+8 gives the product of two numbers which differ by 1.
If k+2 and k-4 have the same number of digits, then k is also in A116132 because k//k+2 = 10^d*k + k + 2 = m*(m+5) then implies k//k-4 = 10^d*k + k - 4 = m*(m+5) - 6 = (m-1)*(m+6). - R. J. Mathar, Aug 10 2008

Examples

			92776472//92776474 = 96320542 * 96320547, where // denotes concatenation.
92776472//92776480 = 96320544 * 96320545.
92776472//92776478 = 96320543 * 96320546.

Crossrefs

Cf. A116158, A116171, A116173, A116179, A116303.
Cf. A116185, A115430, A116205, A116343, A116200, A116330.

Extensions

Edited by N. J. A. Sloane, Apr 15 2007

A116193 Numbers k such that k concatenated with k+5 gives the product of two numbers which differ by 5.

Original entry on oeis.org

11, 45, 18281, 32769, 56891, 180689, 330539, 959481, 1850201, 3247409, 4940219, 2425563239, 2575561739, 6003563495, 7245212645, 7770160145, 4983798265289, 5049762270381, 5534298528989, 5603798594169, 21894082450101
Offset: 1

Views

Author

Giovanni Resta, Feb 06 2006

Keywords

Comments

Also numbers k such that k concatenated with k+9 gives the product of two numbers which differ by 3. For proof that this is the same sequence compare A116133.
Also numbers k such that k concatenated with k-9 gives the product of two numbers which differ by 9.

Examples

			7770160145//7770160136 = 8814851183 * 8814851192, where // denotes concatenation.

Crossrefs

Cf. A116205, A116187, A116349.
Cf. A116179, A115430, A116194, A116200, A116324.
Cf. A116099, A116109, A116231.

Extensions

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

A116205 Numbers k such that k concatenated with k+7 gives the product of two numbers which differ by 3.

Original entry on oeis.org

1, 81, 1353, 3997, 7723, 23761, 26271, 76771, 1415683, 3890571, 8495497, 1066870443, 1239366513, 4198438981, 4534273891, 6502317141, 6918679731, 2199164200036329043, 2820114781174460091, 5500888421709400741
Offset: 1

Views

Author

Giovanni Resta, Feb 06 2006

Keywords

Comments

Also numbers k such that k concatenated with k+9 gives the product of two numbers which differ by 1.
Also numbers k such that k concatenated with k-3 gives the product of two numbers which differ by 7.

Crossrefs

Cf. A116179, A116172, A115429, A116173, A116193, A116336.
Cf. A116132, A116099, A116139, A116152, A116269, A116348.

Extensions

Edited by N. J. A. Sloane, Apr 13 2007

A116310 n times n+5 gives the concatenation of two numbers m and m+3.

Original entry on oeis.org

2, 4, 88, 3676, 6320, 8786, 48743, 51253, 87617, 3762554, 6237442, 9217100, 3266298274, 3520463764, 6479536232, 6733701722, 8063694648, 8317860138, 4689524709430934474, 5310475290569065522, 7416797436703661747
Offset: 1

Views

Author

Giovanni Resta, Feb 06 2006

Keywords

Crossrefs

Cf. A116179, A116303, A116309, A116311, A116324.
Showing 1-6 of 6 results.

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

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