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 1-3 of 3 results.

A101254 a(n) = sum[i=1,n](i-th prime of Erdős-Selfridge classification i-). Cumulative sums of A101231.

Original entry on oeis.org

2, 31, 98, 277, 1218, 5297, 25686, 90953, 315516, 1294379, 7743358, 54991121, 364542120, 2515329959, 16440340258
Offset: 1

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Author

Jonathan Vos Post, Dec 16 2004

Keywords

Comments

The cumulative sums of the diagonalization of the set of sequences {j-th prime of Erdős-Selfridge classification k+}. The diagonalization itself is in A101231.

Crossrefs

Cf. A101231.

Extensions

More terms from David Wasserman, Mar 26 2008

A101253 a(n) = n-th prime of Erdős-Selfridge classification n+.

Original entry on oeis.org

2, 19, 113, 617, 1877, 8753, 52517, 255043, 1532173, 9287521, 48499459, 353653063, 2136716521, 18171787987, 111795382441
Offset: 1

Views

Author

Jonathan Vos Post, Dec 16 2004

Keywords

Comments

Diagonalization of the Erdős-Selfridge classification of primes n+. See A101231 for diagonalization of the Erdős-Selfridge classification of primes n-.

Examples

			a(1) = 2 because 2 is the first element of A005105.
a(2) = 19 because 19 is the 2nd element of A005106.
a(3) = 113 because 113 is the 3rd element of A005107.
a(4) = 617 because 617 is the 4th element of A005108.
a(5) = 1877 because 1877 is the 5th element of A081633.
a(6) = 8753 because 8753 is the 6th element of A081634.

References

  • R. K. Guy, Unsolved Problems in Number Theory, A18.

Crossrefs

Cf. A101231, A005105, A005106, A005107, A005108, A081633, A081634, A081635, A081636, A081637, A081638, A081639, A005113, A019268.
Cf. A084071, A090468, A129474, A129475.

Extensions

More terms from David Wasserman, Mar 26 2008

A098661 a(n) = sum[i=1,n](i-th prime of Erdős-Selfridge classification i+). Cumulative sums of A101253.

Original entry on oeis.org

2, 21, 134, 751, 2628, 11381, 63898, 318941, 1851114, 11138635, 59638094, 413291157, 2550007678, 20721795665, 132517178106
Offset: 1

Views

Author

Jonathan Vos Post, Dec 19 2004

Keywords

Comments

The cumulative sums of the diagonalization of the set of sequences {j-th prime of Erdős-Selfridge classification k+}. The diagonalization itself is in A101253. a(1) = 2 and a(4) = 751 are primes. a(2) = 21 = 3 * 7, a(3) = 134 = 2 * 67; and a(6) = 11381 = 19 * 599 are semiprime. There are only 2 distinct digits in the greatest factor of a(10) = 11138635 = 5 * 2227727. The cumulative sums of the diagonalization of the related set of sequences {j-th prime of Erdős-Selfridge classification k-} is A101254. That n- diagonalization itself is in A101231.

Examples

			a(11) = 59638094 = 2 * 29 * 1028243 = 2+19+113+617+1877+8753+52517+255043+1532173+9287521+48499459

Crossrefs

Cf. A101253, A101254, A101231.

Extensions

More terms from David Wasserman, Mar 26 2008
Showing 1-3 of 3 results.

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