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 1-5 of 5 results.

A076022 Position of 2n in A073662.

Original entry on oeis.org

1, 4, 2, 9, 3, 8, 10, 7, 5, 11, 6, 15, 12, 14, 20, 16, 19, 13, 17, 21, 18, 26, 23, 25, 31, 22, 27, 32, 40, 30, 35, 28, 24, 34, 29, 39, 37, 41, 44, 33, 45, 36, 50, 42, 38, 65, 43, 46, 51, 47, 57, 52, 48, 54, 63, 55, 62, 58, 56, 49, 53, 60, 66, 64, 67, 59, 74, 68, 73, 71, 61, 70
Offset: 1

Views

Author

Zak Seidov, Sep 30 2002

Keywords

Comments

It is not clear that each even number will appear in A073662, though I've checked it up to 20000.

Examples

			a(1)=4 because 2*1=2 appears at 4th position in A073662, a(14)=14 because 2*14=28 appears at 14th position in A073662,

Crossrefs

Cf. A073662, A073664, A076023.

Formula

a(n) = position of (2n) in A073662: A073662(a(n)) = 2n.

A073661 Rearrangement of even numbers such that a(k) + a(k+1) + 1 is a prime for all k.

Original entry on oeis.org

2, 4, 6, 10, 8, 14, 16, 12, 18, 22, 20, 26, 32, 28, 24, 34, 36, 30, 40, 38, 44, 52, 48, 54, 42, 46, 50, 56, 70, 60, 66, 64, 62, 68, 58, 72, 76, 74, 82, 80, 86, 92, 88, 78, 84, 94, 96, 100, 90, 102, 108, 114, 112, 98, 124, 104, 106, 116, 110, 118, 120, 130, 126, 136, 132
Offset: 1

Views

Author

Amarnath Murthy, Aug 10 2002

Keywords

Crossrefs

Cf. A073662, A073664.

Extensions

More terms from Hans Havermann, Sep 23 2002

A073664 Even numbers which retain their relative position in A073661 (are not disturbed in the rearrangement process).

Original entry on oeis.org

2, 4, 6, 18, 28, 56, 60, 64, 68, 72, 80, 116, 126, 152, 170, 184, 200, 214, 234, 248, 276, 290, 328, 330, 334, 346, 360, 402, 408, 416, 438, 472, 512, 524, 578, 598, 662, 702, 744, 786, 810, 824, 864, 908, 968, 1008, 1030, 1032, 1052, 1076, 1172, 1182, 1220
Offset: 0

Views

Author

Amarnath Murthy, Aug 10 2002

Keywords

Crossrefs

Cf. A073661, A073662.

Extensions

More terms from Hans Havermann, Sep 23 2002

A076023 Numbers n such that A076022(n)=n.

Original entry on oeis.org

1, 14, 16, 23, 27, 30, 34, 37, 52, 54, 58, 64, 68, 75, 103, 173, 260, 265, 309, 311, 374, 423, 446, 453, 493, 535, 557, 560, 599, 605, 627, 629, 639, 659, 678, 695, 697, 717, 737, 747, 750, 754, 760, 790, 795, 803, 844, 879, 885, 901, 911, 956, 972, 975, 978
Offset: 1

Views

Author

Zak Seidov, Oct 01 2002

Keywords

Comments

From first 5000 even numbers, 204 retain their place in rearrangement A073662 and they (that is even_number/2) are in the sequence. Positions of each even number in A073662 are in A076022.

Crossrefs

Cf. A073662, A076022.

A073665 Rearrangement of even numbers such that a(n) + a(n+1) + 1 and a(n)*a(n+1) + 1 are primes for all n.

Original entry on oeis.org

2, 8, 14, 32, 20, 26, 62, 38, 50, 56, 80, 68, 110, 86, 140, 98, 74, 122, 104, 128, 152, 44, 92, 134, 212, 176, 170, 146, 116, 200, 158, 224, 194, 164, 218, 242, 188, 272, 284, 308, 254, 314, 278, 290, 230, 248, 182, 206, 302, 296, 260, 326, 332, 350, 236, 320, 266
Offset: 1

Views

Author

Amarnath Murthy, Aug 10 2002

Keywords

Crossrefs

Cf. A073661, A073662, A073664.

Extensions

Corrected and extended by Sascha Kurz, Jan 28 2003
Showing 1-5 of 5 results.

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