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.

A080641 a(1) = 4; for n>1, a(n) is taken to be the smallest integer greater than a(n-1) which is consistent with the condition "n is a member of the sequence if and only if a(n) is divisible by 5".

Original entry on oeis.org

4, 6, 7, 10, 11, 15, 20, 21, 22, 25, 30, 31, 32, 33, 35, 36, 37, 38, 39, 40, 45, 50, 51, 52, 55, 56, 57, 58, 59, 60, 65, 70, 75, 76, 80, 85, 90, 95, 100, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 120, 125, 126, 127, 130, 135, 140, 145, 150, 155, 156, 157
Offset: 1

Views

Author

N. J. A. Sloane and Benoit Cloitre, Feb 28 2003

Keywords

Links

Crossrefs

Cf. A080639, A080640, A079000.

Formula

{a(a(n))} = {5i, i >= 2}.

Extensions

More terms from Matthew Vandermast, Feb 28 2003

A080644 a(1) = 5; for n>1, a(n) is taken to be the smallest integer greater than a(n-1) which is consistent with the condition "n is a member of the sequence if and only if a(n) is divisible by 6".

Original entry on oeis.org

5, 7, 8, 9, 12, 13, 18, 24, 30, 31, 32, 36, 42, 43, 44, 45, 46, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 66, 72, 73, 74, 75, 78, 79, 80, 81, 82, 83, 84, 90, 96, 102, 108, 109, 114, 120, 126, 132, 138, 144, 150, 156, 162, 168, 174, 180, 186, 187, 188, 189, 190
Offset: 1

Views

Author

N. J. A. Sloane and Benoit Cloitre, Feb 28 2003

Keywords

Links

Crossrefs

Cf. A080639, A080640, A079000.

Formula

{a(a(n))} = {6i, i >= 2}.

Extensions

More terms from Matthew Vandermast, Mar 13 2003

A080645 a(1) = 1; for n>1, a(n) is taken to be the smallest integer greater than a(n-1) which is consistent with the condition "for n>1, if n is a member of the sequence then a(n) is even".

Original entry on oeis.org

1, 2, 4, 6, 7, 8, 10, 12, 13, 14, 15, 16, 18, 20, 22, 24, 25, 26, 27, 28, 29, 30, 31, 32, 34, 36, 38, 40, 42, 44, 46, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 66, 68, 70, 72, 74, 76, 78, 80, 82, 84, 86, 88, 90, 92, 94, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107
Offset: 1

Views

Author

N. J. A. Sloane and Benoit Cloitre, Feb 28 2003

Keywords

References

  • Hsien-Kuei Hwang, S Janson, TH Tsai, Exact and asymptotic solutions of the recurrence f(n) = f(floor(n/2)) + f(ceiling(n/2)) + g(n): theory and applications, Preprint, 2016; http://140.109.74.92/hk/wp-content/files/2016/12/aat-hhrr-1.pdf. Also Exact and Asymptotic Solutions of a Divide-and-Conquer Recurrence Dividing at Half: Theory and Applications, ACM Transactions on Algorithms, 13:4 (2017), #47; DOI: 10.1145/3127585

Links

Crossrefs

Cf. A080639, A080640, A079000.
Essentially the same as A007378.

Formula

a(1)=1, a(2)=2, a(3)=4; then for k>=1, abs(j)<=2^k: a(3*2^k+j)=4*2^k+3/2*j+abs(j)/2.
{a(a(n))} = {1, 2, 2i, i >= 3}.

A080646 a(1) = 3; for n>1, a(n) is taken to be the smallest integer greater than a(n-1) which is consistent with the condition "if n is a member of the sequence then a(n) is divisible by 3".

Original entry on oeis.org

3, 4, 8, 12, 13, 14, 15, 16, 17, 18, 19, 20, 24, 28, 32, 36, 40, 44, 48, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 88, 92, 96, 100, 104, 108, 112, 116, 120, 124, 128, 132, 136, 140, 144, 148, 152, 156, 160, 164, 168
Offset: 1

Views

Author

Benoit Cloitre, Feb 12 2003

Keywords

Links

Crossrefs

Cf. A080639, A080640, A079000.

Formula

For k>=2 and i=0, ..., 4^k/2, a((4/3)*(4^(k-1)-1) + i) = (5*4^k-8)/6 + i, a((5*4^k-8)/6 + i) = (4/3)*(4^k-1) + 4*i. - N. J. A. Sloane, Mar 02 2003
{a(a(n))} = {4i, i >= 2}.
Showing 1-4 of 4 results.

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

Content is available under The OEIS End-User License Agreement.