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.

A069614 a(1) = 2; a(2n) = smallest prime starting (the most significant digits) with a(2n-1) (i.e., as a right concatenation of a(2n-1) and a number with no insignificant zeros); a(2n+1) = smallest prime ending in (the least significant digits) a(2n-1). Alternate left and right concatenation yielding primes.

Original entry on oeis.org

2, 23, 223, 2237, 32237, 3223729, 63223729, 632237297, 2632237297, 263223729721, 12263223729721, 1226322372972173, 171226322372972173, 17122632237297217381, 2117122632237297217381, 21171226322372972173813
Offset: 1

Views

Author

Amarnath Murthy, Mar 27 2002

Keywords

Examples

			a(4) = 2111 starting with a(3) = 211 and a(5) = 22111 ending in a(4) = 2111.
		

Crossrefs

Extensions

More terms from Antonio G. Astudillo (afg_astudillo(AT)lycos.com), Mar 30 2003

A069621 a(1) = 9; a(2n) = smallest prime that is a right concatenation of a(2n-1) and a number with no insignificant zeros and a(2n+1) = smallest prime ending in ( the least significant digits) a(2n). Alternate left and right concatenation yielding primes.

Original entry on oeis.org

9, 97, 197, 1973, 31973, 319733, 3319733, 331973311, 6331973311, 633197331131, 5633197331131, 563319733113127, 6563319733113127, 65633197331131279, 3465633197331131279, 346563319733113127933, 18346563319733113127933
Offset: 1

Views

Author

Amarnath Murthy, Mar 27 2002

Keywords

Examples

			a(4) = 1973 starting with a(3) =197 and a(5) = 31973 ending in a(4) = 1973.
		

Crossrefs

Extensions

More terms from Antonio G. Astudillo (afg_astudillo(AT)lycos.com), Mar 30 2003

A069615 a(1) = 3; a(2n) = smallest prime starting (in the most significant digits) with a(2n-1) (i.e., as a right concatenation of a(2n-1) and a number with no insignificant zeros); a(2n+1) = smallest prime ending in (the least significant digits) a(2n-1). Alternate left and right concatenation yielding primes.

Original entry on oeis.org

3, 31, 131, 1319, 21319, 213193, 12213193, 122131939, 1122131939, 112213193957, 27112213193957, 271122131939573, 3271122131939573, 327112213193957339, 2327112213193957339, 232711221319395733969, 13232711221319395733969
Offset: 1

Views

Author

Amarnath Murthy, Mar 27 2002

Keywords

Examples

			a(4) = 1319 starting with a(3) = 131 and a(5) = 21319 ending in a(4) = 1319.
		

Crossrefs

Extensions

More terms from Antonio G. Astudillo (afg_astudillo(AT)lycos.com), Mar 30 2003

A069616 a(1) = 4; a(2n) = smallest prime that is a right concatenation of a(2n-1) and a number with no insignificant zeros and a(2n+1) = smallest prime ending in ( the least significant digits) a(2n-1). Alternate left and right concatenation yielding primes.

Original entry on oeis.org

4, 41, 241, 2411, 32411, 324113, 6324113, 63241133, 1563241133, 15632411339, 815632411339, 81563241133919, 281563241133919, 2815632411339191, 322815632411339191, 32281563241133919151, 432281563241133919151
Offset: 1

Views

Author

Amarnath Murthy, Mar 27 2002

Keywords

Examples

			a(4) = 2411 starting with a(3) =241 and a(5) = 32411 ending in a(4) = 2411.
		

Crossrefs

Extensions

More terms from Antonio G. Astudillo (afg_astudillo(AT)lycos.com), Mar 30 2003

A069617 a(1) = 5; a(2n) = smallest prime that is a right concatenation of a(2n-1) and a number with no insignificant zeros and a(2n+1) = smallest prime ending in ( the least significant digits) a(2n-1). Alternate left and right concatenation yielding primes.

Original entry on oeis.org

5, 53, 353, 3533, 33533, 3353321, 113353321, 1133533213, 101133533213, 10113353321311, 310113353321311, 3101133533213117, 143101133533213117, 14310113353321311739, 314310113353321311739, 314310113353321311739103
Offset: 1

Views

Author

Amarnath Murthy, Mar 27 2002

Keywords

Examples

			a(4) = 3533 starting with a(3) = 353 and a(5) = 33533 ending in a(4) = 3533.
		

Crossrefs

Extensions

More terms from Antonio G. Astudillo (afg_astudillo(AT)lycos.com), Mar 30 2003

A069618 a(1) = 6; a(2n) = smallest prime that is a right concatenation of a(2n-1) and a number with no insignificant zeros and a(2n+1) = smallest prime ending in ( the least significant digits) a(2n-1). Alternate left and right concatenation yielding primes.

Original entry on oeis.org

6, 61, 461, 46133, 246133, 2461337, 22461337, 224613371, 12224613371, 1222461337117, 151222461337117, 15122246133711733, 615122246133711733, 615122246133711733213, 9615122246133711733213, 961512224613371173321349
Offset: 1

Views

Author

Amarnath Murthy, Mar 27 2002

Keywords

Examples

			a(4) = 46133 starting with a(3) = 461 and a(5) = 246133 in a(4) = 46133.
		

Crossrefs

Extensions

More terms from Antonio G. Astudillo (afg_astudillo(AT)lycos.com), Mar 30 2003

A069619 a(1) = 7; a(2n) = smallest prime that is a right concatenation of a(2n-1) and a number with no insignificant zeros and a(2n+1) = smallest prime ending in ( the least significant digits) a(2n-1). Alternate left and right concatenation yielding primes.

Original entry on oeis.org

7, 71, 271, 2711, 52711, 5271121, 135271121, 1352711219, 271352711219, 27135271121911, 1227135271121911, 122713527112191161, 20122713527112191161, 20122713527112191161109, 2720122713527112191161109
Offset: 1

Views

Author

Amarnath Murthy, Mar 27 2002

Keywords

Examples

			a(4) = 2711 starting with a(3) = 271 and a(5) = 52711 in a(4) = 2711.
		

Crossrefs

Extensions

More terms from Antonio G. Astudillo (afg_astudillo(AT)lycos.com), Mar 30 2003

A069620 a(1) = 8; a(2n) = smallest prime that is a right concatenation of a(2n-1) and a number with no insignificant zeros and a(2n+1) = smallest prime ending in ( the least significant digits) a(2n-1). Alternate left and right concatenation yielding primes.

Original entry on oeis.org

8, 83, 283, 2833, 32833, 328331, 2328331, 232833127, 3232833127, 323283312749, 14323283312749, 1432328331274927, 281432328331274927, 28143232833127492741, 3628143232833127492741, 36281432328331274927411
Offset: 1

Views

Author

Amarnath Murthy, Mar 27 2002

Keywords

Examples

			a(4) = 2833 starting with a(3) = 283 and a(5) = 32833 ending in a(4) = 2833.
		

Crossrefs

Extensions

More terms from Antonio G. Astudillo (afg_astudillo(AT)lycos.com), Mar 30 2003
Showing 1-8 of 8 results.