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 1-10 of 10 results.

A329796 Running totals in A329544.

Original entry on oeis.org

1, 4, 2, 7, 3, 22, 33, 11, 5, 22, 8, 0, 7, 22, 6, 33, 9, 22, 4, 33, 7, 44, 77, 33, 5, 44, 8, 33, 3, 44, 6, 55, 9, 44, 4, 55, 7, 66, 111, 101, 33, 1, 22, 2, 11, 66, 8, 55, 5, 66, 6, 77, 11, 88, 111, 99, 11, 202, 303, 414, 505, 393, 424, 505, 626, 757, 898, 828, 696, 616, 494, 404, 262, 88, 131, 77, 5
Offset: 1

Views

Author

N. J. A. Sloane, Dec 10 2019

Keywords

Comments

By construction this is always >= 0 and a palindrome.
For n <= 50000 only two 0 terms have appeared, at n = 12 and 1002.
a(n) = a(n-1) +- A329544(n), using - if A329544(n) is even and otherwise +.

Crossrefs

Cf. A329544.

A329797 Record high water marks in A329544.

Original entry on oeis.org

1, 3, 5, 19, 22, 27, 29, 37, 44, 49, 51, 59, 68, 71, 77, 88, 191, 195, 197, 199, 201, 205, 207, 211, 303, 313, 323, 324, 333, 343, 344, 348, 353, 354, 363, 364, 373, 374, 475, 485, 516, 526, 536, 548, 617, 1609, 1782, 1829, 1921, 2031, 2079, 2195, 2211, 2321
Offset: 1

Views

Author

N. J. A. Sloane, Dec 10 2019

Keywords

Crossrefs

A330311 Where n appears in A329544, or -1 if n never appears.

Original entry on oeis.org

1, 3, 2, 5, 4, 9, 13, 12, 45, 40, 7, 56, 18, 11, 14, 15, 10, 19, 6, 44, 43, 8, 55, 17, 28, 21, 16, 25, 20, 29, 63, 42, 23, 175, 34, 27, 22, 31, 26, 35, 30, 80, 75, 24, 39, 33, 48, 37, 32, 49, 36, 85, 79, 76, 46, 187, 130, 47, 38, 51, 50, 89, 84, 110, 109
Offset: 1

Views

Author

N. J. A. Sloane, Dec 10 2019

Keywords

Comments

a(919) is unknown. If it is not -1, it is greater than 10^6 (see A329544).

Crossrefs

Formula

a(A104444(n)) = -1. - Rémy Sigrist, Dec 11 2019

A329798 Where record high water marks appear in A329544.

Original entry on oeis.org

1, 2, 4, 6, 8, 16, 20, 22, 24, 32, 36, 38, 41, 52, 54, 57, 58, 82, 87, 96, 104, 120, 128, 132, 135, 140, 160, 164, 191, 207, 211, 239, 252, 254, 260, 262, 264, 266, 267, 298, 321, 332, 337, 347, 429, 473, 495, 568, 642, 659, 1058, 1064, 1123, 1132, 1137
Offset: 1

Views

Author

N. J. A. Sloane, Dec 10 2019

Keywords

Crossrefs

A330313 Add the odd terms and subtract the even ones, the result must always be a palindrome in base 3. This is the lexicographically earliest sequence of distinct positive integers with this property.

Original entry on oeis.org

1, 3, 2, 11, 7, 4, 6, 8, 21, 5, 12, 14, 89, 9, 18, 26, 16, 20, 10, 13, 17, 24, 75, 39, 30, 32, 23, 51, 31, 22, 43, 34, 48, 44, 28, 36, 19, 29, 42, 81, 68, 33, 35, 69, 60, 72, 63, 73, 52, 56, 40, 105, 61, 70, 84, 93, 91, 82, 50, 41, 98, 45, 53, 103, 64, 78, 54, 123, 128, 57, 71, 129
Offset: 1

Views

Author

N. J. A. Sloane, Dec 11 2019

Keywords

Comments

A base 3 analog of A329544. The latter has an exceptionally irregular graph, so it is natural to ask if the graph is more understandable in a smaller base (and base 2 does not work).

Crossrefs

Cf. A014190, A329544, A330312, A330314 (running totals).

A330314 Running totals in A330313.

Original entry on oeis.org

1, 4, 2, 13, 20, 16, 10, 2, 23, 28, 16, 2, 91, 100, 82, 56, 40, 20, 10, 23, 40, 16, 91, 130, 100, 68, 91, 142, 173, 151, 194, 160, 112, 68, 40, 4, 23, 52, 10, 91, 23, 56, 91, 160, 100, 28, 91, 164, 112, 56, 16, 121, 182, 112, 28, 121, 212, 130, 80, 121, 23, 68, 121, 224, 160, 82, 28, 151, 23
Offset: 1

Views

Author

N. J. A. Sloane, Dec 11 2019

Keywords

Comments

By construction this is always >= 0 and a palindrome in base 3.
a(n) = a(n-1) +- A330313(n), using - if A330313(n) is even and otherwise +.

Crossrefs

A330401 Lexicographically earliest sequence of distinct positive terms with an associate sequence t such that t(0) = 0, and for any n > 0, at least one of t(n-1) - a(n) or t(n-1) + a(n) is a palindrome; in case t(n-1) - a(n) is a palindrome, set t(n) = t(n-1) - a(n), otherwise set t(n) = t(n-1) + a(n).

Original entry on oeis.org

1, 2, 3, 4, 5, 6, 8, 7, 18, 11, 9, 20, 13, 24, 22, 10, 21, 14, 25, 26, 15, 16, 27, 28, 17, 19, 30, 29, 40, 33, 44, 46, 35, 36, 47, 48, 37, 38, 49, 50, 39, 41, 52, 51, 62, 45, 12, 32, 43, 23, 34, 54, 60, 31, 61, 71, 81, 63, 53, 42, 55, 57, 68, 66, 72, 70, 79
Offset: 1

Views

Author

Rémy Sigrist, Dec 13 2019

Keywords

Comments

This sequence is a variant of A329544.

Examples

			The first terms, alongside t(n), are:
  n   a(n)  t(n)
  --  ----  ----
   0  N/A      0
   1     1     1
   2     2     3
   3     3     0
   4     4     4
   5     5     9
   6     6     3
   7     8    11
   8     7     4
   9    18    22
  10    11    11
  11     9     2
  12    20    22
		

Crossrefs

See A330402 and A330403 for similar sequences.
Cf. A002113, A329544, A330420 (running totals).

Programs

  • PARI
    See Links section.

A330385 Add the odd terms and subtract the even ones, the result must always be a square. This is the lexicographically earliest sequence of distinct positive integers with this property.

Original entry on oeis.org

1, 3, 4, 9, 7, 12, 5, 8, 15, 16, 25, 11, 13, 24, 39, 17, 19, 21, 23, 44, 36, 28, 20, 33, 40, 27, 32, 45, 48, 35, 85, 72, 51, 64, 133, 87, 60, 29, 31, 105, 123, 84, 41, 43, 141, 96, 47, 49, 159, 57, 59, 61, 63, 65, 67, 69, 71, 73, 75, 77, 79, 81, 83, 164, 156
Offset: 1

Views

Author

Rémy Sigrist, Dec 12 2019

Keywords

Comments

This sequence is a variant of A329544.
All terms belong to A042965.

Examples

			The first terms, alongside the corresponding running totals, are:
  n   a(n)  t(n)
  --  ----  --------
   1     1   1 = 1^2
   2     3   4 = 2^2
   3     4   0 = 0^2
   4     9   9 = 3^2
   5     7  16 = 4^2
   6    12   4 = 2^2
   7     5   9 = 3^2
   8     8   1 = 1^2
   9    15  16 = 4^2
  10    16   0 = 0^2
  11    25  25 = 5^2
		

Crossrefs

Cf. A000290, A042965, A329544, A330386 (running totals).

Programs

  • PARI
    s=t=0; for (n=1, 65, for (v=1, oo, if (!bittest(s,v) && issquare(u=t-v*(-1)^v), print1 (v", "); s+=2^v; t=u; break)))

A329545 After a(1) = 1, add the even terms and subtract the odd ones, the result must always be a palindrome. This is the lexicographically earliest sequence of distinct positive integers with this property.

Original entry on oeis.org

1, 2, 3, 4, 18, 11, 5, 16, 13, 7, 6, 14, 15, 26, 22, 33, 17, 28, 25, 36, 35, 9, 8, 58, 55, 44, 46, 10, 20, 30, 73, 77, 66, 24, 40, 50, 103, 79, 68, 34, 23, 81, 48, 47, 80, 83, 72, 54, 43, 85, 52, 49, 38, 37, 70, 64, 53, 87, 32, 27, 60, 57, 90, 12, 45, 59, 92, 42, 75, 61, 94, 62, 95, 63, 74, 69, 194
Offset: 1

Views

Author

Eric Angelini and Jean-Marc Falcoz, Nov 16 2019

Keywords

Comments

Negative palindromes are not allowed. After 50000 terms, the smallest unused integers are 964, 1020, 1029, 1031, 1038, 1041, 1047, 1051, ... and the largest used is 173410. The largest palindrome produced so far is 309903. Is the sequence a permutation of the integers > 0?
a(63411) = 964. Rémy Sigrist's comment in A329544 shows that terms in A104444 are not in the sequence. Conjecture: Sequence is a permutation of positive integers not in A104444. - Chai Wah Wu, Dec 11 2019

Examples

			The sequence starts with 1, smallest positive integer.
1 + 2 = 3 (palindrome)
1 + 2 - 3 = 0 (palindrome)
1 + 2 - 3 + 4 = 1 (palindrome)
1 + 2 - 3 + 4 + 18 = 22 (palindrome)
1 + 2 - 3 + 4 + 18 - 11 = 11 (palindrome)
1 + 2 - 3 + 4 + 18 - 11 - 5 = 6 (palindrome)
1 + 2 - 3 + 4 + 18 - 11 - 5 + 16 = 22 (palindrome), etc.
		

Crossrefs

Cf. A329544 (same idea, but where the odd integers are added and the even ones are subtracted).
Cf. A002113 (palindromes), A086862 (first differences of palindromes).
Cf. A104444.

Programs

  • PARI
    A329545_vec(N, u=1, U, a, s=2, d)={vector(N, n, a=u; while(bittest(U, a-u)|| Vecrev(d=digits(s+(-1)^a*a))!=d|| (a>s&&bittest(a, 0)), a++); s+=(-1)^a*a; U+=1<<(a-u); while(bittest(U, 0), U>>=1; u++); a)} \\ M. F. Hasler, Nov 16 2019

A330325 Positions of 0's in A330314.

Original entry on oeis.org

103, 385, 2059, 2111, 2226, 2312, 2499, 3245, 15952, 16281, 16497, 16640, 18052, 18544, 18562, 18690, 18810, 19111, 19473, 19823, 19889, 19971, 20596, 20678, 21034, 21305, 21703, 21797, 23012, 23105, 23305, 23364, 25090, 25908, 26112, 26574, 27026, 27748
Offset: 1

Views

Author

N. J. A. Sloane, Dec 12 2019

Keywords

Comments

The 0 terms in A329796 seem very scarce, but the present sequence suggests that maybe one needs to search further in that sequence.

Crossrefs

Showing 1-10 of 10 results.