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.

A102138 Iccanobirt prime indices (8 of 15): Indices of prime numbers in A102118.

Original entry on oeis.org

4, 6, 7, 12, 25, 72, 100, 126, 167, 253, 396, 856, 1013, 1172, 1413, 2138, 23926, 28255
Offset: 1

Views

Author

Jonathan Vos Post and Ray Chandler, Dec 31 2004

Keywords

Comments

No more terms through 5000.
a(19) > 50000. - Robert Price, Nov 09 2018

Crossrefs

Cf. A000040, A102118, A102131-A102145.

Programs

  • Mathematica
    a[n_] := a[n] = IntegerReverse[(a[n - 1] + a[n - 2] + a[n - 3])];
a[0] = 0; a[1] = 0; a[2] = 1;
Select[Range[0, 5000], PrimeQ[a[#]] &] (* Robert Price, Apr 10 2020 *)

Formula

A102118(a(n)) = A102158(n).

Extensions

a(17)-a(18) from Robert Price, Nov 09 2018

A102158 Iccanobirt primes (8 of 15): Prime numbers in A102118.

Original entry on oeis.org

2, 7, 31, 31, 97885807, 7105083736241465849989, 386010207538170887319192908532941, 797921272502602257281628706183144343679532451
Offset: 1

Views

Author

Jonathan Vos Post and Ray Chandler, Dec 31 2004

Keywords

Comments

Next term is too large to include.

Crossrefs

Cf. A000040, A102118, A102151-A102165.

Formula

a(n) = A102118(A102138(n)).

Extensions

Offset changed to 1 by Jinyuan Wang, Aug 14 2021

A102178 Iccanobirt semiprime indices (8 of 15): Indices of semiprime numbers in A102118.

Original entry on oeis.org

5, 9, 11, 16, 17, 18, 20, 30, 31, 41, 43, 54, 68, 69, 84, 135, 139, 174, 188, 191, 203, 207, 243, 301, 356
Offset: 1

Views

Author

Jonathan Vos Post and Ray Chandler, Dec 31 2004

Keywords

Crossrefs

Cf. A001358, A102118, A102171-A102185, A102198.

Formula

A102118(a(n)) = A102198(n).

Extensions

a(21)-a(22) from Robert Price, Nov 09 2018
Offset changed to 1 and a(23)-a(25) from Jinyuan Wang, Aug 14 2021

A102198 Iccanobirt semiprimes (8 of 15): Semiprime numbers in A102118.

Original entry on oeis.org

4, 26, 86, 8149, 63071, 16297, 649051, 58252941851, 92725334137, 1053497381056741, 1278670308661982, 94977834729989377, 670970457022641744643, 875040780930863483219, 717513198454659455769232618, 5543447679090248342657818634097933227550696536461
Offset: 1

Views

Author

Jonathan Vos Post and Ray Chandler, Dec 31 2004

Keywords

Crossrefs

Cf. A001358, A102118, A102191-A102205.

Formula

a(n) = A102118(A102178(n)).

Extensions

Offset changed to 1 and more terms from Jinyuan Wang, Aug 14 2021
Showing 1-4 of 4 results.

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

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