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 1-9 of 9 results.

A062339 Primes whose sum of digits is 4.

Original entry on oeis.org

13, 31, 103, 211, 1021, 1201, 2011, 3001, 10111, 20011, 20101, 21001, 100003, 102001, 1000003, 1011001, 1020001, 1100101, 2100001, 10010101, 10100011, 20001001, 30000001, 101001001, 200001001, 1000000021, 1000001011, 1000010101, 1000020001, 1000200001, 1002000001, 1010000011
Offset: 1

Views

Author

Amarnath Murthy, Jun 21 2001

Keywords

Comments

Is this sequence (and its brothers A062337, A062341 and A062343) infinite?
10^A049054(m)+3 and 3*10^A056807(m)+1 are subsequences. A107715 (primes containing only digits from set {0,1,2,3}) is a supersequence. Terms not containing the digit 3 are either terms of A020449 (primes that contain digits 0 and 1 only) or of A106100 (primes with maximal digit 2) - and thus terms of these sequences' union A036953 (primes containing only digits from set {0,1,2}). - Rick L. Shepherd, May 23 2005

Examples

			3001 is a prime with sum of digits = 4, hence belongs to the sequence.
		

Crossrefs

Subsequence of A062338, A107288, and A107715 (primes with digits <= 3).
A159352 is a subsequence.
Cf. A000040 (primes), A052218 (digit sum = 4), A061239 (primes == 4 (mod 9)).
Cf. Primes p with digital sum equal to k: {2, 11 and 101} for k=2; this sequence (k=4), A062341 (k=5), A062337 (k=7), A062343 (k=8), A107579 (k=10), A106754 (k=11), A106755 (k=13), A106756 (k=14), A106757 (k=16), A106758 (k=17), A106759 (k=19), A106760 (k=20), A106761 (k=22), A106762 (k=23), A106763 (k=25), A106764 (k=26), A048517 (k=28), A106766 (k=29), A106767 (k=31), A106768 (k=32), A106769 (k=34), A106770 (k=35), A106771 (k=37), A106772 (k=38), A106773 (k=40), A106774 (k=41), A106775 (k=43), A106776 (k=44), A106777 (k=46), A106778 (k=47), A106779 (k=49), A106780 (k=50), A106781 (k=52), A106782 (k=53), A106783 (k=55), A106784 (k=56), A106785 (k=58), A106786 (k=59), A106787 (k=61), A107617 (k=62), A107618 (k=64), A107619 (k=65), A106807 (k=67), A244918 (k=68), A181321 (k=70).
Cf. A049054 (10^k+3 is prime), A159352 (these primes).
Cf. A056807 (3*10^k+1 is prime), A259866 (these primes).
Cf. A020449 (primes with digits 0 and 1), A036953 (primes with digits <= 2), A106100 (primes with largest digit = 2), A069663, A069664 (smallest resp. largest n-digit prime with minimum digit sum).

Programs

  • Magma
    [p: p in PrimesUpTo(800000000) | &+Intseq(p) eq 4]; // Vincenzo Librandi, Jul 08 2014
  • Maple
    N:= 20: # to get all terms < 10^N
    B[1]:= {1}:
    B[2]:= {2}:
    B[3]:= {3}:
    A:= {}:
    for d from 2 to N do
       B[4]:= map(t -> 10*t+1,B[3]) union  map(t -> 10*t+3,B[1]);
       B[3]:= map(t -> 10*t, B[3]) union map(t -> 10*t+1,B[2]) union map(t -> 10*t+2,B[1]);
       B[2]:= map(t -> 10*t, B[2]) union map(t -> 10*t+1,B[1]);
       B[1]:= map(t -> 10*t, B[1]);
       A:= A union select(isprime,B[4]);
    od:
    sort(convert(A,list)); # Robert Israel, Dec 28 2015
  • Mathematica
    Union[FromDigits/@Select[Flatten[Table[Tuples[{0,1,2,3},k],{k,9}],1],PrimeQ[FromDigits[#]]&&Total[#]==4&]] (* Jayanta Basu, May 19 2013 *)
    FromDigits/@Select[Tuples[{0,1,2,3},10],Total[#]==4&&PrimeQ[FromDigits[#]]&] (* Harvey P. Dale, Jul 23 2025 *)
  • PARI
    for(a=1,20,for(b=0,a,for(c=0,b,if(isprime(k=10^a+10^b+10^c+1),print1(k", "))))) \\ Charles R Greathouse IV, Jul 26 2011
    
  • PARI
    select( {is_A062339(p,s=4)=sumdigits(p)==s&&isprime(p)}, primes([1,10^7])) \\ 2nd optional parameter for similar sequences with other digit sums. M. F. Hasler, Mar 09 2022
    
  • PARI
    A062339_upto_length(L,s=4,a=List(),u=[10^(L-k)|k<-[1..L]])=forvec(d=[[1,L]|i<-[1..s]], isprime(p=vecsum(vecextract(u,d))) && listput(a,p),1); Vecrev(a) \\ M. F. Hasler, Mar 09 2022
    

Formula

Intersection of A052218 (digit sum 4) and A000040 (primes). - M. F. Hasler, Mar 09 2022

Extensions

Corrected and extended by Larry Reeves (larryr(AT)acm.org), Jul 06 2001
More terms from Rick L. Shepherd, May 23 2005
More terms from Lekraj Beedassy, Dec 19 2007

A069665 Smallest n-digit square with maximum digit sum.

Original entry on oeis.org

9, 49, 289, 6889, 97969, 698896, 9696996, 79869969, 876988996, 8998988769, 88998998929, 975979998889, 9998768898889, 97888999968769, 898999897988929, 9895699989899689, 38999699989995889, 989879999979599689
Offset: 1

Views

Author

Amarnath Murthy, Apr 06 2002

Keywords

Crossrefs

Extensions

More terms from Larry Reeves (larryr(AT)acm.org), Oct 14 2003

A069666 Largest n-digit square with maximum digit sum.

Original entry on oeis.org

9, 49, 784, 6889, 97969, 877969, 9696996, 88679889, 876988996, 8998988769, 88998998929, 975979998889, 9998768898889, 97888999968769, 898999897988929, 9896999999766889, 99497897999899876, 989879999979599689
Offset: 1

Views

Author

Amarnath Murthy, Apr 06 2002

Keywords

Crossrefs

Extensions

Corrected and extended by Larry Reeves (larryr(AT)acm.org), Oct 14 2003

A069667 Smallest nontrivial (no trailing zeros) n-digit square with minimum digit sum.

Original entry on oeis.org

1, 16, 121, 1024, 10201, 101124, 1002001, 24000201, 100020001, 2500100001, 10000200001, 141001001001, 1000002000001, 25000010000001, 100000020000001, 2500000100000001, 10000000200000001, 250000001000000001
Offset: 1

Views

Author

Amarnath Murthy, Apr 06 2002

Keywords

Crossrefs

Extensions

More terms from Sascha Kurz, Feb 02 2003
More terms from Larry Reeves (larryr(AT)acm.org), Oct 15 2003

A069668 Largest nontrivial (no trailing zeros) n-digit square with minimum digit sum.

Original entry on oeis.org

1, 25, 121, 2401, 10201, 301401, 1002001, 25010001, 100020001, 2500100001, 10000200001, 250001000001, 1000002000001, 25000010000001, 100000020000001, 2500000100000001, 10000000200000001, 250000001000000001
Offset: 1

Views

Author

Amarnath Murthy, Apr 06 2002

Keywords

Crossrefs

Extensions

Corrected and extended by Larry Reeves (larryr(AT)acm.org), Oct 15 2003

A069669 Smallest n-digit triangular number with maximum digit sum.

Original entry on oeis.org

6, 78, 496, 8778, 58996, 887778, 5897895, 88877778, 686999778, 9876799878, 89996788896, 777887999778, 7798988788878, 77779987999896, 589598998999878, 7898898998885986, 78999997699698778, 999699998689998991
Offset: 1

Views

Author

Amarnath Murthy, Apr 06 2002

Keywords

Crossrefs

Extensions

More terms from Larry Reeves (larryr(AT)acm.org), Oct 15 2003

A069670 Largest n-digit triangular number with maximum digit sum.

Original entry on oeis.org

6, 78, 946, 8778, 58996, 998991, 9979278, 98989485, 886899786, 9998888991, 89996788896, 999998497578, 9869988988965, 99989985868878, 988895779999896, 9999678588989986, 99889886986899778, 999699998689998991
Offset: 1

Views

Author

Amarnath Murthy, Apr 06 2002

Keywords

Crossrefs

Extensions

More terms from Larry Reeves (larryr(AT)acm.org), Oct 15 2003

A069671 Smallest n-digit triangular number with minimum digit sum.

Original entry on oeis.org

1, 10, 120, 2211, 10011, 112101, 2001000, 10006101, 200010000, 1210000221, 20000100000, 210010000005, 2000001000000, 32000004000000, 200000010000000, 3200000040000000, 20000000100000000, 320000000400000000, 2000000001000000000, 32000000004000000000
Offset: 1

Views

Author

Amarnath Murthy, Apr 06 2002

Keywords

Comments

Does the obvious pattern continue? - Vladeta Jovovic, Apr 07 2002

Crossrefs

Extensions

More terms from Vladeta Jovovic, Apr 07 2002
More terms from Sean A. Irvine, May 12 2024

A069672 Largest n-digit triangular number with minimum digit sum.

Original entry on oeis.org

1, 10, 300, 3003, 20100, 112101, 2001000, 33020001, 200010000, 3200120001, 20000100000, 320001200001, 2000001000000, 32000012000001, 200000010000000, 3200000120000001, 20000000100000000, 320000001200000001, 2000000001000000000, 32000000012000000001, 200000000010000000000, 3200000000120000000001, 20000000000100000000000, 320000000001200000000001, 2000000000001000000000000, 32000000000012000000000001, 200000000000010000000000000, 3200000000000120000000000001, 20000000000000100000000000000, 320000000000001200000000000001
Offset: 1

Views

Author

Amarnath Murthy, Apr 06 2002

Keywords

Comments

Does the obvious pattern continue? - Vladeta Jovovic, Apr 07 2002

Crossrefs

Programs

  • Maple
    F:= proc(d)
    local s, P, nP, S, x, bestx;
    bestx:= 0;
    for s in [1,3,6,9] do
      for P in map(op @combinat:-permute, combinat:-partition(s)) do
        nP:= nops(P);
        for S in map(t -> [d-1, op(t)], combinat:-choose([$0..d-2],nP-1)) do
          x:= add(P[i]*10^S[i],i=1..nP);
          if x > bestx and issqr(1+8*x) then bestx:= x fi;
        od;
      od;
      if bestx > 0 then return bestx fi;
    od;
    end proc:
    seq(F(d),d=1..30); # Robert Israel, May 25 2016

Extensions

More terms from Vladeta Jovovic, Apr 07 2002
a(15)..a(30) from Robert Israel, May 25 2016
Showing 1-9 of 9 results.