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 1-7 of 7 results.

A083997 Primes arising in A083996.

Original entry on oeis.org

313, 93139, 3931393, 11393139311, 1113931393111, 23111393139311123, 492311139313931112349, 2149231113931393111234921, 321492311139313931112349213, 1732149231113931393111234921317
Offset: 1

Views

Author

Amarnath Murthy, May 23 2003

Keywords

Crossrefs

Cf. A083996, A083998, A083999, A084000, A083401.

Extensions

More terms from Ray Chandler, Jun 22 2003

A083998 a(1) = 3; then numbers such that the concatenation a(n)a(n-1)...a(2)a(1)a(2)...a(n-1)a(n) is a prime.

Original entry on oeis.org

3, 1, 1, 23, 21, 3, 67, 17, 3, 39, 19, 33, 21, 39, 77, 121, 207, 9, 9, 93, 53, 1, 57, 93, 41, 339, 9, 57, 63, 1, 1091, 273, 199, 83, 213, 529, 569, 397, 21, 71, 481, 243, 111, 419, 273, 231, 63, 277, 483, 201, 531, 77, 139, 1313, 529, 1443, 587, 649, 351, 273, 189
Offset: 1

Views

Author

Amarnath Murthy, May 23 2003

Keywords

Crossrefs

Cf. A083996, A083997, A083999, A084000, A083401.

Extensions

More terms from Ray Chandler, Aug 03 2003

A083999 Primes arising in A083998.

Original entry on oeis.org

3, 131, 11311, 231131123, 2123113112321, 321231131123213, 6732123113112321367, 17673212311311232136717, 3176732123113112321367173, 39317673212311311232136717339, 193931767321231131123213671733919
Offset: 1

Views

Author

Amarnath Murthy, May 23 2003

Keywords

Crossrefs

Cf. A083996, A083997, A083998, A084000, A084001.

Extensions

More terms from Ray Chandler, Jun 22 2003

A084000 a(1) = 7; then numbers such that the concatenation a(n)a(n-1)...a(2)a(1)a(2)...a(n-1)a(n) is a prime.

Original entry on oeis.org

7, 3, 9, 17, 19, 9, 93, 29, 69, 27, 37, 33, 57, 41, 31, 167, 111, 1, 3, 267, 119, 87, 121, 671, 363, 393, 87, 241, 131, 151, 29, 21, 277, 273, 219, 119, 517, 251, 433, 93, 39, 731, 1593, 321, 579, 279, 687, 691, 629, 939, 943, 831, 513, 449, 1813, 413, 187, 947, 79
Offset: 1

Views

Author

Amarnath Murthy, May 23 2003

Keywords

Crossrefs

Cf. A083996, A083997, A083998, A083999, A084001.

Extensions

More terms from Ray Chandler, Aug 03 2003

A084001 Primes arising in A084000.

Original entry on oeis.org

7, 373, 93739, 179373917, 1917937391719, 919179373917199, 9391917937391719993, 29939191793739171999329, 692993919179373917199932969, 2769299391917937391719993296927, 37276929939191793739171999329692737
Offset: 1

Views

Author

Amarnath Murthy, May 23 2003

Keywords

Crossrefs

Cf. A083996, A083997, A083998, A083999, A084000.

Extensions

More terms from Ray Chandler, Jun 22 2003

A084002 a(1) = 9; then numbers such that the concatenation a(n)a(n-1)...a(2)a(1)a(2)...a(n-1)a(n) is a prime for n>1.

Original entry on oeis.org

9, 1, 7, 17, 9, 9, 1, 51, 29, 21, 49, 107, 37, 63, 329, 69, 93, 1, 53, 9, 79, 219, 267, 59, 457, 189, 599, 277, 743, 67, 59, 379, 33, 231, 83, 381, 451, 11, 451, 791, 289, 323, 87, 241, 447, 189, 189, 1107, 903, 393, 219, 629, 931, 797, 49, 261, 233, 93, 1239, 663
Offset: 1

Views

Author

Amarnath Murthy, May 23 2003

Keywords

Examples

			191, 71917, 177191717, ... are prime.

Crossrefs

Cf. A083996, A083997, A083998, A083999, A084000, A084001, A084003.

Programs

  • Python
    from sympy import isprime
def aupton(terms):
    alst, astr = [9], "9"
    for n in range(2, terms+1):
        an = 1
        while not isprime(int(str(an) + astr + str(an))): an += 1
        alst.append(an); astr = str(an) + astr + str(an)
    return alst
print(aupton(60)) # Michael S. Branicky, Sep 01 2021

Extensions

More terms from Ray Chandler, Aug 03 2003

A084003 Primes arising in A084002.

Original entry on oeis.org

191, 71917, 177191717, 91771917179, 9917719171799, 199177191717991, 5119917719171799151, 29511991771917179915129, 212951199177191717991512921, 4921295119917719171799151292149
Offset: 1

Views

Author

Amarnath Murthy, May 23 2003

Keywords

Crossrefs

Cf. A083996, A083997, A083998, A083999, A084000, A084001, A084002.

Extensions

More terms from Ray Chandler, Jun 22 2003
Showing 1-7 of 7 results.

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

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