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.

User: E.J.P. Vening

E.J.P. Vening's wiki page.

E.J.P. Vening has authored 10 sequences.

A147781 1 - A147850(n).

Original entry on oeis.org

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

Author

E.J.P. Vening, Nov 12 2008

Keywords

Comments

Old name was: Odd/even binary expansion of summed, partitioned subsequent prime numbers. The sum of 8 subsequent prime numbers is multiplied, forming a new sum. The digits of each sum are added per digit, forming a new sum. The odd or even result is visualized by 0/1.

Examples

			2+3+5+7+11+13+17+19 = 1384614, 1+3+8+4+6+1+4 = 27 (odd/0).
23+29+31+37+41+43+47+53 = 5466528, 5+4+6+6+5+2+8 = 36 (even/1).
461+463+467+479+487+491+499+503 = 69230700, 6+9+2+3+7 = 27 (odd/0).
509+521+523+541+547+557+563+569 = 77862060 , 7+7+8+6+2+6 = 36 (even/1).
		

Formula

a(n) = 1 - A147850(n).

Extensions

More terms and better name by Joerg Arndt, Aug 28 2013

A147873 A sequence based on the mechanics of A147781: b(n) = Apply[Plus, IntegerDigits( 17982*Sum_{m=0..7} Prime(n+m) )]; a(n) = 1-(b(n) mod 2).

Original entry on oeis.org

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

Author

E.J.P. Vening and Roger L. Bagula, Nov 16 2008

Keywords

Programs

  • Mathematica
    a[n_] := Apply[Plus, IntegerDigits[27*666*Sum[Prime[n + m], {m, 0, 7}]]]; Table[1 - Mod[a[n], 2], {n, 1, 100}]

A147850 Parity of the digits sum of Sum_{j = 8*n-7..8*n} prime(j).

Original entry on oeis.org

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

Author

E.J.P. Vening, Nov 15 2008

Keywords

Examples

			2+3+5+7+11+13+17+19 = 1384614 (1+3+8+4+6+1+4) = 27 (1).
23+29+31+37+41+43+47+53 = 5466528 (5+4+6+6+5+2+8) = 36 (0).
461+463+467+479+487+491+499+503 = 69230700 (6+9+2+3+7) = 27 (1).
509+521+523+541+547+557+563+569 = 77862060 (7+7+8+6+2+6) = 36 (0).
		

Crossrefs

Cf. A147781.

Programs

Formula

a(n) = 1 - A147781(n).
a(n) = A007953(17982*A127335(8*n-7)) mod 2. - R. J. Mathar, Jan 06 2009

Extensions

More terms from R. J. Mathar, Jan 06 2009

A152010 Sum of digits of A127335(n).

Original entry on oeis.org

14, 17, 7, 6, 9, 3, 6, 9, 7, 7, 12, 12, 10, 15, 6, 15, 15, 8, 12, 21, 12, 21, 10, 18, 24, 19, 21, 4, 12, 6, 11, 15, 12, 18, 6, 12, 9, 13, 13, 12, 17, 11, 14, 11, 21, 11, 18, 10, 14, 20, 8, 16, 4, 10, 16, 12, 15, 14, 15, 15, 17, 18, 11, 21, 15, 15, 17, 20, 12, 18, 3, 15, 20, 9, 21, 10, 6
Offset: 1

Author

E.J.P. Vening and Roger L. Bagula, Nov 19 2008

Keywords

Programs

  • Mathematica
    Table[Apply[Plus, IntegerDigits[Sum[Prime[n + m], {m, 0, 7}]]], {n, 1, 100}]

Formula

a(n) = A007953( A127335(n) ). [Joerg Arndt, Aug 28 2013]

A117722 a(n) = A000045(A003622(n)).

Original entry on oeis.org

1, 3, 8, 34, 144, 377, 1597, 4181, 17711, 75025, 196418, 832040, 3524578, 9227465, 39088169, 102334155, 433494437, 1836311903, 4807526976, 20365011074, 53316291173, 225851433717, 956722026041, 2504730781961, 10610209857723
Offset: 0

Author

E.J.P. Vening, Apr 13 2006

Keywords

Comments

Old name was: Fibonacci numbers from sequence A000045 aligned with instances of '1' in the Fibonacci word sequence A003849.

Crossrefs

Programs

Formula

a(n) = A000045( A003622(n) ). - Joerg Arndt, Aug 28 2013

Extensions

More terms from R. J. Mathar, Jan 21 2008
Better name by Joerg Arndt, Aug 28 2013

A109755 Row and column sums of A001223 ( Differences between consecutive primes - see example ).

Original entry on oeis.org

1, 3, 9, 21, 51, 117, 251, 523, 1077, 2207, 4521, 9283
Offset: 0

Author

E.J.P. Vening, Aug 11 2005

Keywords

Comments

Resembles the first 6 entries of sequence A005254 (number of weighted voting procedures).

Examples

			Column A - Primes (for reference)
Column B - Distance between consecutive primes
A B
2 1
3 2 3
5 2
7 4 6 9
11 2
13 4 6
17 2
19 4 6 12 21
23 6
29 2 8
31 6
37 4 10 18 30 51
41 2
43 4 6
47 6
53 6 12 18 36 66 117
59 2
61 6 8
67 4
71 2 6 14 32 68 134 251
		

Crossrefs

A109635 Sum of prime(n) and n-th digit of Pi after the decimal point.

Original entry on oeis.org

3, 7, 6, 12, 20, 15, 23, 24, 26, 34, 39, 46, 48, 52, 50, 55, 62, 69, 71, 77, 75, 85, 87, 92, 100, 109, 106, 109, 116, 122, 132, 131, 139, 147, 157, 155, 158, 172, 174, 174, 185, 190, 194, 202, 206, 202, 218, 228, 228, 229, 238, 247, 243, 251, 266, 270, 273, 280
Offset: 1

Author

E.J.P. Vening, Aug 03 2005

Keywords

Comments

In some cases n resembles the prime number in the subsequent prime row. Some slight intervals can be observed: for example 599(593+6) to 641(641+0) to 691(683+8) to 743(743+0) to 809(811+2), each 8 rows apart and 3 instances 10 rows apart.

Examples

			The first column gives the primes, the second column the digits of Pi and the third column their sum.
2 1 3
3 4 7
5 1 6
7 5 12
...
		

Programs

  • Mathematica
    Total/@With[{nn=60},Thread[{Prime[Range[nn]],Rest[RealDigits[Pi,10,nn+1][[1]]]}]] (* Harvey P. Dale, Apr 25 2020 *)

Formula

a(n) ~ n log n.

A109652 a(n) = prime(A000201(n)).

Original entry on oeis.org

2, 5, 7, 13, 19, 23, 31, 37, 43, 53, 59, 67, 73, 79, 89, 97, 103, 109, 113, 131, 137, 149, 157, 163, 173, 181, 191, 197, 199, 223, 229, 233, 241, 257, 263, 271, 277, 283, 307, 311, 317, 331, 347, 353, 359, 373, 383, 389, 401, 409, 421, 433, 439, 449, 457, 463
Offset: 1

Author

E.J.P. Vening, Aug 05 2005

Keywords

Crossrefs

Programs

  • PARI
    a(n) = prime(n*(1+sqrt(5))\2); \\ Michel Marcus, Aug 28 2013
    
  • Python
    from math import isqrt
    from sympy import prime
    def A109652(n): return prime(n+isqrt(5*n**2)>>1) # Chai Wah Wu, Aug 10 2022

Formula

a(n) ~ phi*n*log n, where phi = (1+sqrt(5))/2. - Charles R Greathouse IV, Apr 19 2015

Extensions

Better description from Joseph Biberstine and Graeme McRae, Aug 05 2006

A109654 Primes A000040(i) such that A003849(i-1) = 1.

Original entry on oeis.org

3, 11, 17, 29, 41, 47, 61, 71, 83, 101, 107, 127, 139, 151, 167, 179, 193, 211, 227, 239, 251, 269, 281, 293, 313, 337, 349, 367, 379, 397, 419, 431, 443, 461, 467, 491, 503, 523, 557, 569, 587, 599, 613, 631, 643, 659, 677, 691, 719, 733, 751, 769, 787, 811, 823, 839, 859, 877, 887
Offset: 1

Author

E.J.P. Vening, Aug 05 2005

Keywords

Comments

Original sequence name: Primes aligned with instances of '1' in the infinite Fibonacci word sequence A003849.

Crossrefs

Cf. A003849.

Programs

  • PARI
    a(n) = prime(floor(n*((sqrt(5)+1)/2)^2)) /* Georg Fischer, Sep 21 2024 */

Formula

a(n) = A000040(A003622(n) + 1) = prime(floor(n*phi^2)), where phi = (1+sqrt(5))/2 is the golden ration. - Charles R Greathouse IV and Danny Rorabaugh, Apr 21 2015

Extensions

Name clarified by Danny Rorabaugh, Apr 19 2015
a(21)=251 inserted and more terms from Georg Fischer, Sep 21 2024

A102022 First differences of A109652.

Original entry on oeis.org

3, 2, 6, 6, 4, 8, 6, 6, 10, 6, 8, 6, 6, 10, 8, 6, 6, 4, 18, 6, 12, 8, 6, 10, 8, 10, 6, 2, 24, 6, 4, 8, 16, 6, 8, 6, 6, 24, 4, 6, 14, 16, 6, 6, 14, 10, 6, 12, 8, 12, 12, 6, 10, 8, 6, 16, 8, 12, 10, 12, 20, 6, 16, 8, 6, 16, 8, 6, 10, 2, 22, 6, 6, 8, 12, 10, 18, 8, 18, 12, 4, 14, 4, 12, 24, 12, 12, 6, 2, 24, 4
Offset: 1

Author

E.J.P. Vening, Jun 19 2007

Keywords

Crossrefs

Cf. A109652.

Programs

  • Mathematica
    Differences[Table[Prime[Floor[n*GoldenRatio]], {n, 1, 92}]] (* James C. McMahon, Jan 06 2024 *)

Extensions

Terms corrected and more terms added, Joerg Arndt, Aug 28 2013