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.

A277025 n for which A277023(4n) is square, thus A277024(4n) is zero.

Original entry on oeis.org

0, 1, 2, 3, 4, 5, 6, 9, 10, 12, 14, 15, 17, 18, 20, 21, 23, 24, 26, 28, 30, 31, 33, 34, 35, 36, 37, 39, 40, 41, 42, 44, 45, 48, 51, 52, 54, 55, 56, 57, 58, 60, 63, 66, 68, 69, 70, 71, 72, 74, 78, 80, 81, 84, 88, 90, 91, 93, 95, 96, 98, 99, 102, 105, 107, 108, 110, 111, 112, 114, 117, 118, 120, 121, 123, 126, 129, 131
Offset: 0

Views

Author

Antti Karttunen, Oct 03 2016

Keywords

Comments

Indexing starts from zero because a(0)=0 is a special case in this sequence.

Crossrefs

Complement: A277026.

A277024 a(n) = A277023(n) - n^2.

Original entry on oeis.org

0, 2, 2, 2, 0, 2, 2, 2, 0, 2, 2, 2, 0, 2, 2, 2, 0, 2, 2, 0, 0, 3, 2, 2, 0, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 0, 2, 2, 2, 0, 2, 3, 2, 2, 0, 2, 2, 0, 2, 2, 2, 2, 2, 2, 2, 0, 2, 2, 2, 0, 2, 2, 2, 2, 2, 2, 2, 0, 2, 2, 2, 0, 2, 2, 2, 2, 2, 2, 2, 0, 2, 2, 0, 0, 2, 2, 2, 2, 2, 2, 2, 0, 2, 2, 2, 0, 2, 2, 2, 2, 2, 2, 2, 0, 2, 3, 2, 2, 0, 2, 2, 0, 2, 2, 2, 2, 2, 2, 2, 0
Offset: 0

Views

Author

Antti Karttunen, Oct 03 2016

Keywords

Crossrefs

Cf. A277015 (positions of zeros), A277025 (positions where 4n is zero), A277026 (where 4n is nonzero).

Programs

Formula

a(n) = A277023(n) - n^2.

A277026 n for which A277023(4n) is not a square, thus A277024(4n) is nonzero.

Original entry on oeis.org

7, 8, 11, 13, 16, 19, 22, 25, 27, 29, 32, 38, 43, 46, 47, 49, 50, 53, 59, 61, 62, 64, 65, 67, 73, 75, 76, 77, 79, 82, 83, 85, 86, 87, 89, 92, 94, 97, 100, 101, 103, 104, 106, 109, 113, 115, 116, 119, 122, 124, 125, 127, 128, 130, 133, 134, 137, 140, 141, 143, 145, 146, 148, 151, 152, 154, 155, 163, 164, 167, 168, 169, 170, 173, 174, 176, 178, 179, 181, 184, 185
Offset: 1

Views

Author

Antti Karttunen, Oct 03 2016

Keywords

Crossrefs

Complement: A277025.
Cf. A277024.

A277015 Numbers whose squares are present in A276573 (the infinite trunk of least squares beanstalk).

Original entry on oeis.org

0, 4, 8, 12, 16, 19, 20, 24, 36, 40, 45, 48, 56, 60, 68, 72, 80, 83, 84, 92, 96, 104, 109, 112, 120, 124, 132, 136, 140, 144, 147, 148, 156, 160, 164, 168, 173, 176, 180, 192, 204, 208, 211, 216, 220, 224, 228, 232, 237, 240, 252, 264, 272, 275, 276, 280, 284
Offset: 0

Views

Author

Antti Karttunen, Oct 03 2016

Keywords

Comments

Indexing starts from zero because a(0)=0 is a special case in this sequence.

Crossrefs

Cf. A000196, A002828, A276573, A277014, A277016 (the corresponding squares), A277025 (multiples of four present / 4).
Positions of squares in A277023, zeros in A277024.

Programs

Formula

A276574 The infinite trunk of least squares beanstalk with reversed subsections.

Original entry on oeis.org

0, 3, 8, 6, 15, 11, 24, 21, 18, 16, 35, 32, 30, 27, 48, 45, 43, 40, 38, 63, 59, 56, 53, 51, 80, 78, 75, 72, 70, 67, 64, 99, 96, 93, 90, 88, 85, 83, 120, 117, 115, 112, 108, 105, 102, 143, 139, 136, 134, 131, 128, 126, 123, 168, 165, 162, 160, 158, 155, 152, 149, 147, 144, 195, 192, 189, 186, 183, 179, 176, 173, 171
Offset: 0

Views

Author

Antti Karttunen, Sep 07 2016

Keywords

Examples

			This can be viewed as an irregular table, where after 0, each row has A260734(n) = 1, 2, 2, 4, 4, 5, 5, 7, ... terms:
0;
3;
8, 6;
15, 11;
24, 21, 18, 16;
35, 32, 30, 27;
48, 45, 43, 40, 38;
63, 59, 56, 53, 51;
80, 78, 75, 72, 70, 67, 64;
99, 96, 93, 90, 88, 85, 83;
120, 117, 115, 112, 108, 105, 102;
...
Each row begins with (n^2)-1 (see A005563), and each successive term is obtained by subtracting A002828(k) from the previous term k, until ((n-1)^2)-1 would be encountered, which is not listed second time (as it already occurs as the first term of the previous row), but instead, the current row is finished and the next row is started with the term ((n+1)^2)-1.
		

Crossrefs

Cf. A005563 (left edge), A277023 (right edge).
Used to construct A276573.
Cf. A277015 (tells which rows end with squares, listed in A277016).

Programs

  • Scheme
    (definec (A276574 n) (cond ((zero? n) n) ((= 1 n) 3) (else (let ((maybe_next (A255131 (A276574 (- n 1))))) (if (zero? (A010052 (+ 1 maybe_next))) maybe_next (+ -1 (A000290 (+ 2 (A000196 (+ 1 maybe_next))))))))))

Formula

a(0) = 0; a(1) = 3; for n > 1, let k = A255131(a(n-1)). If k+1 is not a square, then a(n) = k, otherwise a(n) = A000290(2+A000196(k+1)) - 1.

Extensions

Example section added and the formula rewritten to a simpler form (which is now correct) - Antti Karttunen, Oct 16 2016
Showing 1-5 of 5 results.