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 16 results. Next

A099655 a[n]=A098085[n]-A096215[n], difference between next and previous primes to A011974[n], the sum of two consecutive primes.

Original entry on oeis.org

4, 4, 2, 2, 6, 2, 6, 2, 6, 2, 4, 6, 6, 8, 4, 4, 14, 4, 2, 10, 6, 6, 6, 10, 2, 12, 12, 12, 12, 2, 6, 6, 6, 10, 14, 4, 14, 14, 10, 4, 8, 6, 6, 8, 8, 10, 6, 8, 8, 2, 12, 8, 8, 6, 12, 18, 18, 10, 6, 6, 6, 2, 2, 12, 12, 6, 12, 8, 10, 8, 10, 8, 4, 6, 8, 4, 14, 12, 2, 2, 14, 14, 14, 14, 2, 20, 20, 8, 10, 8
Offset: 1

Views

Author

Labos Elemer, Nov 17 2004

Keywords

Examples

			n=8, p(8)+p(9)=19+23=42,a[8]=43-41=2=a(8).
		

Crossrefs

Programs

  • Mathematica
    <Harvey P. Dale, Mar 07 2017 *)

Formula

a(n)=NextPrime[p(n)+p(n+1)]-PreviousPrime[p(n)+p(n+1)]

A034961 Sums of three consecutive primes.

Original entry on oeis.org

10, 15, 23, 31, 41, 49, 59, 71, 83, 97, 109, 121, 131, 143, 159, 173, 187, 199, 211, 223, 235, 251, 269, 287, 301, 311, 319, 329, 349, 371, 395, 407, 425, 439, 457, 471, 487, 503, 519, 533, 551, 565, 581, 589, 607, 633, 661, 679, 689, 701, 713, 731, 749, 771
Offset: 1

Views

Author

Patrick De Geest, Oct 15 1998

Keywords

Comments

For prime terms see A034962. - Zak Seidov, Feb 17 2011

Examples

			a(1) = 10 = 2 + 3 + 5.
a(42) = 565 = 181 + 191 + 193.
		

Crossrefs

Programs

  • Magma
    [&+[ NthPrime(n+k): k in [0..2] ]: n in [1..50] ]; // Vincenzo Librandi, Apr 03 2011
    
  • Mathematica
    Plus @@@ Partition[ Prime[ Range[60]], 3, 1] (* Robert G. Wilson v, Feb 11 2005 *)
    3 MovingAverage[Prime[Range[60]], {1, 1, 1}] (* Jean-François Alcover, Nov 12 2018 *)
  • PARI
    a(n)=my(p=prime(n),q=nextprime(p+1)); p+q+nextprime(q+1) \\ Charles R Greathouse IV, Jul 01 2013
    
  • PARI
    is(n)=my(p=precprime(n\3),q=nextprime(n\3+1),r=n-p-q); if(r>q, r==nextprime(q+2), r==precprime(p-1) && r) \\ Charles R Greathouse IV, Jul 05 2017
    
  • Python
    from sympy import nextprime
    from itertools import count, islice
    def agen(): # generator of terms
        p, q, r = 2, 3, 5
        while True:
            yield p + q + r
            p, q, r = q, r, nextprime(r)
    print(list(islice(agen(), 54))) # Michael S. Branicky, Dec 27 2022
  • Sage
    BB = primes_first_n(57)
    L = []
    for i in range(55):
        L.append(BB[i]+BB[i+1]+BB[i+2])
    L # Zerinvary Lajos, May 14 2007
    

Formula

a(n) = Sum_{k=0..2} A000040(n+k). - Omar E. Pol, Feb 28 2020
a(n) = A001043(n) + A000040(n+2). - R. J. Mathar, May 25 2020

A034963 Sums of four consecutive primes.

Original entry on oeis.org

17, 26, 36, 48, 60, 72, 88, 102, 120, 138, 152, 168, 184, 202, 220, 240, 258, 272, 290, 306, 324, 348, 370, 390, 408, 420, 432, 456, 480, 508, 534, 556, 576, 596, 620, 638, 660, 682, 700, 724, 744, 762, 780, 800, 830, 860, 890, 912, 928, 942, 964, 988, 1012
Offset: 1

Views

Author

Patrick De Geest, Oct 15 1998

Keywords

Examples

			a(7) = 17 + 19 + 23 + 29 = 88.
		

Crossrefs

Programs

Formula

a(n) = Sum_{k=0..3} A000040(n+k). - Omar E. Pol, Mar 02 2020

A034962 Primes that are the sum of three consecutive primes.

Original entry on oeis.org

23, 31, 41, 59, 71, 83, 97, 109, 131, 173, 199, 211, 223, 251, 269, 311, 349, 439, 457, 487, 503, 607, 661, 701, 829, 857, 883, 911, 941, 1033, 1049, 1061, 1151, 1187, 1229, 1249, 1303, 1367, 1381, 1409, 1433, 1493, 1511, 1553, 1667, 1867, 1931, 1973, 1993
Offset: 1

Views

Author

Patrick De Geest, Oct 15 1998

Keywords

Comments

Or, primes in A034961 (Sums of three consecutive primes). - Zak Seidov, Feb 16 2011

Examples

			E.g., 131 = 41 + 43 + 47.
A034962(n) = p+q+r, where p = A073681(n), and p<q<r are three consecutive primes. - _Zak Seidov_, Mar 09 2009
		

Crossrefs

Cf. A001043, A011974, A034707, A034961. Different from A050207.
Cf. A073681 (smallest of three consecutive primes whose sum is a prime).

Programs

  • Magma
    [a: n in [1..150] | IsPrime(a) where a is NthPrime(n)+NthPrime(n+1)+NthPrime(n+2)]; // Vincenzo Librandi, Jun 23 2016
    
  • Maple
    a:=proc(n) if isprime(ithprime(n)+ithprime(n+1)+ithprime(n+2))=true then ithprime(n)+ithprime(n+1)+ithprime(n+2) else fi end: seq(a(n), n=1..120); # Emeric Deutsch, Apr 24 2006
  • Mathematica
    a = {}; Do[k = Prime[x] + Prime[x + 1] + Prime[x + 2]; If[PrimeQ[k], AppendTo[a, k]], {x, 1, 350}]; a (* Artur Jasinski, Jan 27 2007 *)
    Select[(Plus@@@Partition[Prime[Range[200]],3,1]),PrimeQ] (* Zak Seidov, Feb 07 2012 *)
    Select[ListConvolve[{1,1,1},Prime[Range[200]]],PrimeQ] (* Harvey P. Dale, Jul 12 2013 *)
  • PARI
    forprime(p=2,1000, p2=nextprime(p+1); p3=nextprime(p2+1); q=p+p2+p3; if(isprime(q),print1(q",")) ) \\ Max Alekseyev, Jan 26 2007
    
  • PARI
    {p=2;q=3;for(n=1,100,r=nextprime(q+1); if(isprime(t=p+q+r),print1(t","));p=q;q=r;)} \\ Zak Seidov, Mar 09 2009
    
  • Python
    from itertools import count, islice
    from sympy import isprime, nextprime
    def agen(): # generator of terms
        p, q, r = 2, 3, 5
        while True:
            if isprime(p+q+r): yield p+q+r
            p, q, r = q, r, nextprime(r)
    print(list(islice(agen(), 50))) # Michael S. Branicky, Dec 27 2022

A034964 Sums of five consecutive primes.

Original entry on oeis.org

28, 39, 53, 67, 83, 101, 119, 139, 161, 181, 199, 221, 243, 263, 287, 311, 331, 351, 373, 395, 421, 449, 473, 497, 517, 533, 559, 587, 617, 647, 683, 707, 733, 759, 787, 811, 839, 863, 891, 917, 941, 961, 991, 1023, 1057, 1089, 1123, 1151, 1169, 1193
Offset: 1

Views

Author

Patrick De Geest, Oct 15 1998

Keywords

Comments

Except for the first term, all terms are odd. - Alonso del Arte, Dec 30 2011

Examples

			a(1) = prime(1+0) + prime(1+1) + prime(1+2) + prime(1+3) + prime(1+4) = 2 + 3 + 5 + 7 + 11 = 28.
a(2) = prime(2+0) + prime(2+1) + prime(2+2) + prime(2+3) + prime(2+4) = 3 + 5 + 7 + 11 + 13 = 39.
		

References

  • Owen O'Shea and Underwood Dudley, The Magic Numbers of the Professor, Mathematical Association of America (2007), p. 62

Crossrefs

Cf. A131686 (sums of five consecutive squares of primes).

Programs

  • Magma
    [&+[ NthPrime(n+k): k in [0..4] ]: n in [1..100] ]; // Vincenzo Librandi, Apr 03 2011
    
  • Maple
    A034964:=n->add(ithprime(i), i=n..n+4): seq(A034964(n), n=1..50); # Wesley Ivan Hurt, Sep 14 2014
  • Mathematica
    Plus@@@Partition[Prime[Range[100]],5,1] (* Vladimir Joseph Stephan Orlovsky, Feb 18 2010 *)
  • PARI
    a(n) = sum(k=n, n+4, prime(k)); \\ Michel Marcus, Sep 03 2016
    
  • PARI
    first(n) = {my(psum = 28, pr = List([2,3,5,7,11]), res = List([28])); for(i=2,n, psum -= pr[1]; listpop(pr, 1); listput(pr, nextprime(pr[4] + 1)); psum += pr[5]; listput(res, psum)); res} \\ David A. Corneth, Oct 14 2017
  • Sage
    BB = primes_first_n(60)
    L = []
    for i in range(55):
        L.append(BB[i]+BB[i+1]+BB[i+2]+BB[i+3]+BB[i+4])
    L # Zerinvary Lajos, May 14 2007
    

Formula

a(n) = Sum_{i=n..n+4} prime(i). - Wesley Ivan Hurt, Sep 14 2014

Extensions

Offset changed to 1 by Joerg Arndt, Sep 04 2016

A034965 Primes that are sum of five consecutive primes.

Original entry on oeis.org

53, 67, 83, 101, 139, 181, 199, 263, 311, 331, 373, 421, 449, 587, 617, 647, 683, 733, 787, 811, 839, 863, 941, 991, 1123, 1151, 1193, 1361, 1381, 1579, 1609, 1801, 1831, 1861, 1949, 1979, 2081, 2113, 2143, 2221, 2273, 2297, 2357, 2423, 2459, 2689, 2731
Offset: 1

Views

Author

Patrick De Geest, Oct 15 1998

Keywords

Examples

			53 = 5 + 7 + 11 + 13 + 17.
373 = 67 + 71 + 73 + 79 + 83.
		

Crossrefs

Cf. A001043, A011974, A034707, A152468. Also Cf. A034964, of which this sequence is a subset.

Programs

  • Maple
    ts_prod_n:=proc(n) local i,ans; ans:=[ ]: for i from 1 to n do if isprime(ithprime(i)+ithprime(i+1)+ithprime(i+2)+ithprime(i+3)+ithprime(i+4))= 'true' then ans:=[op(ans), ithprime(i)+ithprime(i+1)+ithprime(i+2)+ithprime(i+3)+ithprime(i+4) ]: fi od: end: ts_prod_n(701); # Jani Melik, May 05 2006
  • Mathematica
    Select[Table[Plus@@Prime[Range[n, n + 4]], {n, 200}], PrimeQ] (* Alonso del Arte, Dec 30 2011 *)
    Select[Total/@Partition[Prime[Range[200]],5,1],PrimeQ] (* Harvey P. Dale, May 24 2012 *)

Extensions

Corrected example by Paul S. Coombes, Dec 29 2011

A127337 Numbers that are the sum of 10 consecutive primes.

Original entry on oeis.org

129, 158, 192, 228, 264, 300, 340, 382, 424, 468, 510, 552, 594, 636, 682, 732, 780, 824, 870, 912, 954, 1008, 1060, 1114, 1164, 1216, 1266, 1320, 1376, 1434, 1494, 1546, 1596, 1650, 1704, 1752, 1800, 1854, 1914, 1974, 2030, 2084, 2142, 2192, 2250, 2310, 2374
Offset: 1

Views

Author

Artur Jasinski, Jan 11 2007

Keywords

Comments

a(n) is the absolute value of coefficient of x^9 of the polynomial Product_{j=0..9} (x - prime(n+j)) of degree 10; the roots of this polynomial are prime(n), ..., prime(n+9).

Crossrefs

Programs

  • Magma
    [&+[ NthPrime(n+k): k in [0..9] ]: n in [1..90] ]; // Vincenzo Librandi, Apr 03 2011
    
  • Maple
    A127337 := proc(n)
        local i ;
        add(ithprime(n+i),i=0..9) ;
    end proc:
    seq(A127337(n),n=1..30) ; # R. J. Mathar, Apr 24 2023
  • Mathematica
    a = {}; Do[AppendTo[a, Sum[Prime[x + n], {n, 0, 9}]], {x, 1, 50}]; a
    Table[Plus@@Prime[Range[n, n + 9]], {n, 50}] (* Alonso del Arte, Feb 15 2011 *)
    ListConvolve[ConstantArray[1, 10], Prime[Range[50]]]
    Total/@Partition[Prime[Range[60]],10,1] (* Harvey P. Dale, Jan 31 2013 *)
  • PARI
    {m=46;k=10;for(n=1,m,print1(a=sum(j=0,k-1,prime(n+j)),","))} \\ Klaus Brockhaus, Jan 13 2007
    
  • PARI
    {m=46;k=10;for(n=1,m,print1(abs(polcoeff(prod(j=0,k-1,(x-prime(n+j))),k-1)),","))} \\ Klaus Brockhaus, Jan 13 2007
    
  • Python
    from sympy import prime
    def a(n): return sum(prime(n + i) for i in range(10))
    print([a(n) for n in range(1, 48)]) # Michael S. Branicky, Dec 09 2021
    
  • Python
    # faster version for generating initial segment of sequence
    from sympy import nextprime
    def aupton(terms):
        alst, plst = [], [2, 3, 5, 7, 11, 13, 17, 19, 23, 29]
        for n in range(terms):
            alst.append(sum(plst))
            plst = plst[1:] + [nextprime(plst[-1])]
        return alst
    print(aupton(47)) # Michael S. Branicky, Dec 09 2021

Formula

a(n) = A127336(n)+A000040(n+9). - R. J. Mathar, Apr 24 2023

Extensions

Edited by Klaus Brockhaus, Jan 13 2007

A127333 Numbers that are the sum of 6 consecutive primes.

Original entry on oeis.org

41, 56, 72, 90, 112, 132, 156, 180, 204, 228, 252, 280, 304, 330, 358, 384, 410, 434, 462, 492, 522, 552, 580, 606, 630, 660, 690, 724, 756, 796, 834, 864, 896, 926, 960, 990, 1020, 1054, 1084, 1114, 1140, 1172, 1214, 1250, 1286, 1322, 1362, 1392, 1420
Offset: 1

Views

Author

Artur Jasinski, Jan 11 2007

Keywords

Comments

a(n) is the absolute value of coefficient of x^5 of the polynomial Prod_{j=0,5}(x-prime(n+j)) of degree 6; the zeros of this polynomial are prime(n), ..., prime(n+5).

Crossrefs

Programs

  • Magma
    [&+[ NthPrime(n+k): k in [0..5] ]: n in [1..80] ]; /* Vincenzo Librandi, Apr 03 2011 */
  • Mathematica
    a = {}; Do[AppendTo[a, Sum[Prime[x + n], {n, 0, 5}]], {x, 1, 50}]; a
    Total/@Partition[Prime[Range[60]],6,1] (* Harvey P. Dale, Mar 12 2015 *)
  • PARI
    {m=50;k=6;for(n=0,m-1,print1(a=sum(j=1,k,prime(n+j)),","))} \\ Klaus Brockhaus, Jan 12 2007
    
  • PARI
    {m=50;k=6;for(n=1,m,print1(abs(polcoeff(prod(j=0,k-1,(x-prime(n+j))),k-1)),","))} \\ Klaus Brockhaus, Jan 12 2007
    

Extensions

Edited by Klaus Brockhaus, Jan 12 2007

A127335 Numbers that are the sum of 8 successive primes.

Original entry on oeis.org

77, 98, 124, 150, 180, 210, 240, 270, 304, 340, 372, 408, 442, 474, 510, 546, 582, 620, 660, 696, 732, 768, 802, 846, 888, 928, 966, 1012, 1056, 1104, 1154, 1194, 1236, 1278, 1320, 1362, 1404, 1444, 1480, 1524, 1574, 1622, 1670, 1712, 1758, 1802, 1854, 1900
Offset: 1

Views

Author

Artur Jasinski, Jan 11 2007

Keywords

Comments

a(n) is the absolute value of coefficient of x^7 of the polynomial Prod_{j=0,7}(x-prime(n+j)) of degree 8; the roots of this polynomial are prime(n), ..., prime(n+7).

Crossrefs

Programs

  • Magma
    [&+[ NthPrime(n+k): k in [0..7] ]: n in [1..90] ]; // Vincenzo Librandi, Apr 03 2011
  • Maple
    S:= [0,op(ListTools:-PartialSums(select(isprime, [2,seq(i,i=3..1000,2)])))]:
    S[9..-1]-S[1..-9]; # Robert Israel, Nov 27 2017
  • Mathematica
    a = {}; Do[AppendTo[a, Sum[Prime[x + n], {n, 0, 7}]], {x, 1, 50}]; a
    Total/@Partition[Prime[Range[60]],8,1] (* Harvey P. Dale, Sep 10 2019 *)
  • PARI
    {m=48;k=8;for(n=1,m,print1(a=sum(j=0,k-1,prime(n+j)),","))} \\ Klaus Brockhaus, Jan 13 2007
    
  • PARI
    {m=48;k=8;for(n=1,m,print1(abs(polcoeff(prod(j=0,k-1,(x-prime(n+j))),k-1)),","))} \\ Klaus Brockhaus, Jan 13 2007
    
  • PARI
    a(n)=my(p=prime(n));p+sum(i=2,8,p=nextprime(p+1)) \\ Charles R Greathouse IV, Apr 19 2015
    

Formula

a(n) ~ 8n log n. - Charles R Greathouse IV, Apr 19 2015

Extensions

Edited by Klaus Brockhaus, Jan 13 2007

A127336 Numbers that are the sum of 9 consecutive primes.

Original entry on oeis.org

100, 127, 155, 187, 221, 253, 287, 323, 363, 401, 439, 479, 515, 553, 593, 635, 679, 721, 763, 803, 841, 881, 929, 977, 1025, 1067, 1115, 1163, 1213, 1267, 1321, 1367, 1415, 1459, 1511, 1555, 1601, 1643, 1691, 1747, 1801, 1851, 1903, 1951, 1999, 2053
Offset: 1

Views

Author

Artur Jasinski, Jan 11 2007

Keywords

Comments

a(n) = absolute value of coefficient of x^8 of the polynomial Product_{j=0..8}(x - prime(n+j)) of degree 9; the roots of this polynomial are prime(n), ..., prime(n+8).

Crossrefs

Programs

  • Magma
    [&+[ NthPrime(n+k): k in [0..8] ]: n in [1..100] ]; // Vincenzo Librandi, Apr 03 2011
    
  • Mathematica
    A127336 = {}; Do[AppendTo[A127336, Sum[Prime[x + n], {n, 0, 8}]], {x, 1, 50}]; A127336 (* Artur Jasinski, Jan 11 2007 *)
    Table[Plus@@Prime[Range[n, n + 8]], {n, 50}] (* Alonso del Arte, Aug 27 2013 *)
    Total/@Partition[Prime[Range[60]],9,1] (* Harvey P. Dale, Nov 18 2020 *)
  • PARI
    {m=46;k=9;for(n=1,m,print1(a=sum(j=0,k-1,prime(n+j)),","))} \\ Klaus Brockhaus, Jan 13 2007
    {m=46;k=9;for(n=1,m,print1(abs(polcoeff(prod(j=0,k-1,(x-prime(n+j))),k-1)),","))} \\ Klaus Brockhaus, Jan 13 2007
    
  • Python
    from sympy import prime
    def a(x): return sum([prime(x + n) for n in range(9)])
    print([a(i) for i in range(1, 50)]) # Indranil Ghosh, Mar 18 2017

Formula

a(n) = A127335(n)+A000040(n+8). - R. J. Mathar, Apr 24 2023

Extensions

Edited by Klaus Brockhaus, Jan 13 2007
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