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.

A202342 Numbers occurring exactly twice in Hofstadter H-sequence A005374.

Original entry on oeis.org

1, 4, 5, 7, 10, 13, 14, 17, 18, 20, 23, 24, 26, 29, 32, 33, 35, 38, 41, 42, 45, 46, 48, 51, 54, 55, 58, 59, 61, 64, 65, 67, 70, 73, 74, 77, 78, 80, 83, 84, 86, 89, 92, 93, 95, 98, 101, 102, 105, 106, 108, 111, 112, 114, 117, 120, 121, 123, 126, 129, 130, 133
Offset: 1

Views

Author

Reinhard Zumkeller, Dec 17 2011

Keywords

Comments

Position of the n-th occurrence of the digit 1 in A105083(n-1) for n>=1. - Jeffrey Shallit, Mar 08 2025

Crossrefs

Cf. A005374, A105083, A202340, A136495, A136496, A202341 (complement).

Programs

  • Haskell
    import Data.List (elemIndices)
    a202342 n = a202342_list !! (n-1)
    a202342_list = elemIndices 2 a202340_list

Formula

A202340(a(n)) = 2.
a(n) = A005374(A136496(n)). - Alan Michael Gómez Calderón, Dec 22 2024
a(n) = A136495(A136495(n)). - Alan Michael Gómez Calderón, Jan 06 2025

A020942 First column of 3rd-order Zeckendorf array A136189.

Original entry on oeis.org

1, 5, 7, 10, 14, 18, 20, 24, 26, 29, 33, 35, 38, 42, 46, 48, 51, 55, 59, 61, 65, 67, 70, 74, 78, 80, 84, 86, 89, 93, 95, 98, 102, 106, 108, 112, 114, 117, 121, 123, 126, 130, 134, 136, 139, 143, 147, 149, 153, 155, 158, 162, 164, 167, 171, 175, 177, 180, 184
Offset: 1

Views

Author

Keywords

Comments

I would like to get similar sequences where the least term in the representation is 2 [gives 2 8 11 15 21 27 30..., which is now A064105], 3, 4, 6, etc. They are the 2nd, 3rd, etc. columns of the 3rd-order Zeckendorf array. [See cross-references. - N. J. A. Sloane, Apr 29 2024]
These have now been entered in the OEIS as
column 1: A020942.
column 2: A064105.
column 3: A064106.
column 4: A372749.
column 5: A372750.
column 6: A372752.
column 7: A372756.
column 8: A372757.

Examples

			1=1; 5=4+1; 7=6+1; 10=9+1; etc.
		

Crossrefs

Formula

Any number n has unique representation as a sum of terms from {1, 2, 3, 4, 6, 9, 13, 19, ...} (cf. A000930) such that no two terms are adjacent or pen-adjacent; e.g., 7=6+1. Sequence gives all n where that representation involves 1.
Conjecture: a(n) = A202342(n) + n. - Sean A. Irvine, May 05 2019 [proved in corrected form in Shallit (2025); it should read a(n) = A202342(n) + n-1]
a(n) = A136496(n) - 1. - Jeffrey Shallit, Mar 08 2025

Extensions

More terms from Naohiro Nomoto, Sep 17 2001

A136495 Solution of the complementary equation b(n)=a(a(n))+n.

Original entry on oeis.org

1, 3, 4, 5, 7, 9, 10, 12, 13, 14, 16, 17, 18, 20, 22, 23, 24, 26, 28, 29, 31, 32, 33, 35, 37, 38, 40, 41, 42, 44, 45, 46, 48, 50, 51, 53, 54, 55, 57, 58, 59, 61, 63, 64, 65, 67, 69, 70, 72, 73, 74, 76, 77, 78, 80, 82, 83, 84, 86, 88, 89, 91, 92, 93, 95, 97, 98, 100, 101, 102
Offset: 1

Views

Author

Clark Kimberling, Jan 01 2008

Keywords

Comments

b = 1 + (column 1 of Z) = 1 + A020942. The pair (a,b) also satisfy the following complementary equations: b(n)=a(a(a(n)))+1; a(b(n))=a(n)+b(n); b(a(n))=a(n)+b(n)-1; (and others).
Let Z = (3rd order Zeckendorf array) = A136189. Then a = ordered union of columns 1,3,4,6,7,9,10,12,13,... of Z, b = ordered union of columns 2,5,8,11,14,... of Z.
Position of the n-th occurrence of either 1 or 3 in A105083(n-1) for n>=1. - Jeffrey Shallit, Mar 08 2025

Examples

			b(1) = a(a(1))+1 = a(1)+1 = 1+1 = 2;
b(2) = a(a(2))+2 = a(3)+2 = 4+2 = 6;
b(3) = a(a(3))+3 = a(4)+3 = 5+3 = 8;
b(4) = a(a(4))+4 = a(5)+4 = 7+4 = 11.
		

References

  • Clark Kimberling and Peter J. C. Moses, Complementary equations and Zeckendorf arrays, in Applications of Fibonacci Numbers, vol.10, Proceedings of the Thirteenth International Conference on Fibonacci Numbers and Their Applications, William Webb, editor, Congressus Numerantium, Winnipeg, Manitoba 201 (2010) 161-178.

Crossrefs

Programs

  • Haskell
    import Data.List (elemIndex)
    import Data.Maybe (fromJust)
    a136495 n = (fromJust $ n `elemIndex` tail a005374_list) + 1
    -- Reinhard Zumkeller, Dec 17 2011

Formula

A005374(a(n)) = n. - Reinhard Zumkeller, Dec 17 2011
a(n) = A005374(A005374(n-1)) + n. - Alan Michael Gómez Calderón, Jul 16 2025

A372749 4th column of the 3-Zeckendorf array (A136189).

Original entry on oeis.org

4, 17, 23, 32, 45, 58, 64, 77, 83, 92, 105, 111, 120, 133, 146, 152, 161, 174, 187, 193, 206, 212, 221, 234, 247, 253, 266, 272, 281, 294, 300, 309, 322, 335, 341, 354, 360, 369, 382, 388, 397, 410, 423, 429, 438, 451, 464, 470, 483, 489, 498, 511, 517, 526, 539
Offset: 1

Views

Author

A.H.M. Smeets, May 12 2024

Keywords

Comments

The 3-Zeckendorf array (A136189) is based on the Narayana (Narayana's cow sequence A000930) weighted representation of n (see A350215).

Crossrefs

The k-th row: A000930(n+2) (k=1)
The k-th column: A020942 (k=1), A064105 (k=2), A064106 (k=3), this sequence (k=4), A372750 (k=5).
The k-th prepended column: A005374 (k=1), A202342 (k=4)

Formula

a(n) = A202342(n) + A136496(n) + A381841(n) - 2. - Jeffrey Shallit, Mar 08 2025

A372750 5th column of the 3-Zeckendorf array (A136189).

Original entry on oeis.org

6, 25, 34, 47, 66, 85, 94, 113, 122, 135, 154, 163, 176, 195, 214, 223, 236, 255, 274, 283, 302, 311, 324, 343, 362, 371, 390, 399, 412, 431, 440, 453, 472, 491, 500, 519, 528, 541, 560, 569, 582, 601, 620, 629, 642, 661, 680, 689, 708, 717, 730, 749, 758, 771
Offset: 1

Views

Author

A.H.M. Smeets, May 12 2024

Keywords

Comments

The 3-Zeckendorf array (A136189) is based on the Narayana (Narayana's cow sequence A000930) weighted representation of n (see A350215).

Crossrefs

The k-th row: A000930(n+2) (k=1)
The k-th column: A020942 (k=1), A064105 (k=2), A064106 (k=3), A372749 (k=4), this sequence (k=5).
The k-th prepended column: A005374 (k=1), A202342 (k=4)

Formula

a(n) = A202342(n) + A136496(n) + 2*A381841(n) - 3. - Jeffrey Shallit, Mar 08 2025

A372752 6th column of the 3-Zeckendorf array (A136189).

Original entry on oeis.org

9, 37, 50, 69, 97, 125, 138, 166, 179, 198, 226, 239, 258, 286, 314, 327, 346, 374, 402, 415, 443, 456, 475, 503, 531, 544, 572, 585, 604, 632, 645, 664, 692, 720, 733, 761, 774, 793, 821, 834, 853, 881, 909, 922, 941, 969, 997, 1010, 1038, 1051, 1070, 1098
Offset: 1

Views

Author

A.H.M. Smeets, May 12 2024

Keywords

Comments

The 3-Zeckendorf array (A136189) is based on the Narayana (Narayana's cow sequence A000930) weighted representation of n (see A350215).

Crossrefs

The k-th row: A000930(n+2) (k=1)
The k-th column: A020942 (k=1), A064105 (k=2), A064106 (k=3), A372749 (k=4), A372750 (k=5), this sequence (k=6).
The k-th prepended column: A005374 (k=1), A202342 (k=4)

Formula

a(n) = 2*A202342(n) + A136496(n) + 3*A381841(n) - 4. - Jeffrey Shallit, Mar 08 2025

A381841 Position of the n-th occurrence of the digit 3 in A105083(n-1) for n>=1.

Original entry on oeis.org

3, 9, 12, 16, 22, 28, 31, 37, 40, 44, 50, 53, 57, 63, 69, 72, 76, 82, 88, 91, 97, 100, 104, 110, 116, 119, 125, 128, 132, 138, 141, 145, 151, 157, 160, 166, 169, 173, 179, 182, 186, 192, 198, 201, 205, 211, 217, 220, 226, 229, 233, 239, 242, 246, 252, 258
Offset: 1

Views

Author

Jeffrey Shallit, Mar 08 2025

Keywords

Crossrefs

Formula

a(n) = A064105(n) + 1.
a(n) = A136495(n) + A136496(n).

A372756 7th column of the 3-Zeckendorf array (A136189).

Original entry on oeis.org

13, 54, 73, 101, 142, 183, 202, 243, 262, 290, 331, 350, 378, 419, 460, 479, 507, 548, 589, 608, 649, 668, 696, 737, 778, 797, 838, 857, 885, 926, 945, 973, 1014, 1055, 1074, 1115, 1134, 1162, 1203, 1222, 1250, 1291, 1332, 1351, 1379, 1420, 1461, 1480, 1521
Offset: 1

Views

Author

A.H.M. Smeets, May 12 2024

Keywords

Comments

The 3-Zeckendorf array (A136189) is based on the Narayana (Narayana's cow sequence A000930) weighted representation of n (see A350215).

Crossrefs

The k-th row: A000930(n+2) (k=1), A372760 (k=2).
The k-th column: A020942 (k=1), A064105 (k=2), A064106 (k=3), A372749 (k=4), A372750 (k=5), A372752 (k=6), this sequence (k=7), A372757 (k=8).
The k-th prepended column: A005374 (k=1), A136495 (k=2), A023443 (k=3), A202342 (k=4), A372758 (k=5), A372759 (k=6).

Formula

a(n) = 3*A202342(n) + 2*A136496(n) + 4*A381841(n) - 6. - Jeffrey Shallit, Mar 08 2025

A372757 8th column of the 3-Zeckendorf array (A136189).

Original entry on oeis.org

19, 79, 107, 148, 208, 268, 296, 356, 384, 425, 485, 513, 554, 614, 674, 702, 743, 803, 863, 891, 951, 979, 1020, 1080, 1140, 1168, 1228, 1256, 1297, 1357, 1385, 1426, 1486, 1546, 1574, 1634, 1662, 1703, 1763, 1791, 1832, 1892, 1952, 1980, 2021, 2081, 2141
Offset: 1

Views

Author

A.H.M. Smeets, May 12 2024

Keywords

Comments

The 3-Zeckendorf array (A136189) is based on the Narayana (Narayana's cow sequence A000930) weighted representation of n (see A350215).

Crossrefs

The k-th row: A000930(n+2) (k=1), A372760 (k=2).
The k-th column: A020942 (k=1), A064105 (k=2), A064106 (k=3), A372749 (k=4), A372750 (k=5), A372752 (k=6), A372756 (k=7), this sequence (k=8).
The k-th prepended column: A005374 (k=1), A136495 (k=2), A023443 (k=3), A202342 (k=4), A372758 (k=5), A372759 (k=6).

Formula

a(n) = 4*A202342(n) + 3*A136496(n) + 6*A381841(n) - 9. - Jeffrey Shallit, Mar 08 2025

A138253 Beatty discrepancy of the complementary equation b(n) = a(a(n)) + n.

Original entry on oeis.org

1, 2, 1, 1, 0, 1, 1, 1, 0, 1, 0, 1, 0, 1, 2, 1, 1, 0, 1, 0, 2, 1, 1, 0, 1, 0, 0, 0, 1, 1, 1, 1, 0, 2, 1, 1, 0, 1, 0, 0, 1, 1, 0, 1, 1, 0, 1, 1, 1, 1, 1, 0, 1, 0, 1, 0, 1, 0, 0, 1, 1, 2, 1, 1, 0, 1, 0, 1, 0, 1, 0, 1, 1, 0, 2, 1, 1, 0, 1, 0, 1, 1, 1, 0, 1, 0, 0, 2, 1, 2, 1, 1, 0, 1, 1, 1, 0, 1, 0, 1, 0, 1, 2, 1, 1
Offset: 1

Views

Author

Clark Kimberling, Mar 09 2008

Keywords

Comments

Suppose that (a(n)) and (b(n)) are complementary sequences that satisfy a complementary equation b(n) = f(a(n), n) and that the limits r = lim_{n->inf} a(n)/n and s = lim_{n->inf} b(n)/n exist and are both in the open interval (0,1). Let c(n) = floor(a(n)) and d(n) = floor(b(n)), so that (c(n)) and (d(n)) are a pair of Beatty sequences. Define e(n) = d(n) - f(c(n), n). The sequence (e(n)) is here introduced as the Beatty discrepancy of the complementary equation b(n) = f(a(n), n). In the case at hand, (e(n)) measures the closeness of the pair (A136495, A136496) to the Beatty pair (A138251, A138252).

Examples

			d(1) - c(c(1)) - 1 =  3 - 1 - 1 = 1;
d(2) - c(c(2)) - 2 =  6 - 2 - 2 = 2;
d(3) - c(c(3)) - 3 =  9 - 5 - 3 = 1;
d(4) - c(c(4)) - 4 = 12 - 7 - 4 = 1.
		

Crossrefs

Formula

A138253(n) = d(n) - c(c(n)) - n, where c(n) = A138251(n), d(n) = A138252(n).
Showing 1-10 of 10 results.