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 11 results. Next

A052217 Numbers whose sum of digits is 3.

Original entry on oeis.org

3, 12, 21, 30, 102, 111, 120, 201, 210, 300, 1002, 1011, 1020, 1101, 1110, 1200, 2001, 2010, 2100, 3000, 10002, 10011, 10020, 10101, 10110, 10200, 11001, 11010, 11100, 12000, 20001, 20010, 20100, 21000, 30000, 100002, 100011, 100020, 100101
Offset: 1

Views

Author

Henry Bottomley, Feb 01 2000

Keywords

Comments

From Joshua S.M. Weiner, Oct 19 2012: (Start)
Sequence is a representation of the "energy states" of "multiplex" notation of 3 quantum of objects in a juggling pattern.
0 = an empty site, or empty hand. 1 = one object resides in the site. 2 = two objects reside in the site. 3 = three objects reside in the site. (See A038447.) (End)
A007953(a(n)) = 3; number of repdigits = #{3,111} = A242627(3) = 2. - Reinhard Zumkeller, Jul 17 2014
Can be seen as a table whose n-th row holds the n-digit terms {10^(n-1) + 10^m + 10^k, 0 <= k <= m < n}, n >= 1. Row lengths are then (1, 3, 6, 10, ...) = n*(n+1)/2 = A000217(n). The first and the n last terms of row n are 10^(n-1) + 2 resp. 2*10^(n-1) + 10^k, 0 <= k < n. - M. F. Hasler, Feb 19 2020

Crossrefs

Cf. A007953, A218043 (subsequence).
Row n=3 of A245062.
Other digit sums: A011557 (1), A052216 (2), A052218 (4), A052219 (5), A052220 (6), A052221 (7), A052222 (8), A052223 (9), A052224 (10), A166311 (11), A235151 (12), A143164 (13), A235225(14), A235226 (15), A235227 (16), A166370 (17), A235228 (18), A166459 (19), A235229 (20).
Other bases: A014311 (binary), A226636 (ternary), A179243 (Zeckendorf).
Cf. A003056, A002262 (triangular coordinates), A056556, A056557, A056558 (tetrahedral coordinates).

Programs

  • Haskell
    a052217 n = a052217_list !! (n-1)
    a052217_list = filter ((== 3) . a007953) [0..]
    -- Reinhard Zumkeller, Jul 17 2014
    
  • Magma
    [n: n in [1..100101] | &+Intseq(n) eq 3 ]; // Vincenzo Librandi, Mar 07 2013
    
  • Mathematica
    Union[FromDigits/@Select[Flatten[Table[Tuples[Range[0,3],n],{n,6}],1],Total[#]==3&]] (* Harvey P. Dale, Oct 20 2012 *)
    Select[Range[10^6], Total[IntegerDigits[#]] == 3 &] (* Vincenzo Librandi, Mar 07 2013 *)
    Union[Flatten[Table[FromDigits /@ Permutations[PadRight[s, 18]], {s, IntegerPartitions[3]}]]] (* T. D. Noe, Mar 08 2013 *)
  • PARI
    isok(n) = sumdigits(n) == 3; \\ Michel Marcus, Dec 28 2015
    
  • PARI
    apply( {A052217_row(n,s,t=-1)=vector(n*(n+1)\2,k,t++>s&&t=!s++;10^(n-1)+10^s+10^t)}, [1..5]) \\ M. F. Hasler, Feb 19 2020
    
  • Python
    from itertools import count, islice
    def agen(): yield from (10**i + 10**j + 10**k for i in count(0) for j in range(i+1) for k in range(j+1))
    print(list(islice(agen(), 40))) # Michael S. Branicky, May 14 2022
    
  • Python
    from math import comb, isqrt
    from sympy import integer_nthroot
    def A052217(n): return 10**((m:=integer_nthroot(6*n,3)[0])-(a:=n<=comb(m+2,3)))+10**((k:=isqrt(b:=(c:=n-comb(m-a+2,3))<<1))-((b<<2)<=(k<<2)*(k+1)+1))+10**(c-1-comb(k+(b>k*(k+1)),2)) # Chai Wah Wu, Dec 11 2024

Formula

T(n,k) = 10^(n-1) + 10^A003056(k) + 10^A002262(k) when read as a table with row lengths n*(n+1)/2, n >= 1, 0 <= k < n*(n+1)/2. - M. F. Hasler, Feb 19 2020
a(n) = 10^A056556(n-1) + 10^A056557(n-1) + 10^A056558(n-1). - Kevin Ryde, Apr 17 2021

Extensions

Offset changed from 0 to 1 by Vincenzo Librandi, Mar 07 2013

A179242 Numbers that have two terms in their Zeckendorf representation.

Original entry on oeis.org

4, 6, 7, 9, 10, 11, 14, 15, 16, 18, 22, 23, 24, 26, 29, 35, 36, 37, 39, 42, 47, 56, 57, 58, 60, 63, 68, 76, 90, 91, 92, 94, 97, 102, 110, 123, 145, 146, 147, 149, 152, 157, 165, 178, 199, 234, 235, 236, 238, 241, 246, 254, 267, 288, 322, 378, 379, 380, 382, 385, 390
Offset: 1

Views

Author

Emeric Deutsch, Jul 05 2010

Keywords

Comments

A007895(a(n)) = 2. - Reinhard Zumkeller, Mar 10 2013

Examples

			4 = 1+3;
6 = 1+5;
7 = 2+5;
9 = 1+8;
10 = 2+8;
		

Crossrefs

Programs

  • Haskell
    import Data.List (inits)
    a179242 n = a179242_list !! (n-1)
    a179242_list = concatMap h $ drop 3 $ inits $ drop 2 a000045_list where
       h is = reverse $ map (+ f) fs where
              (f:_:fs) = reverse is
    -- Reinhard Zumkeller, Mar 10 2013
    
  • Maple
    with(combinat): B := proc (n) local A, ct, m, j: A := proc (n) local i; for i while fibonacci(i) <= n do n-fibonacci(i) end do end proc: ct := 0: m := n: for j while 0 < A(m) do ct := ct+1: m := A(m) end do: ct+1 end proc: Q := {}: for i from fibonacci(5)-1 to 400 do if B(i) = 2 then Q := `union`(Q, {i}) else end if end do: Q;
  • Mathematica
    f[n_] := (k = 1; ff = {}; While[(fi = Fibonacci[k]) <= n, AppendTo[ff, fi]; k++]; Drop[ff, 1]); z[n_] := If[n == 0, 0, r = n; s = {}; fr = f[n]; While[r > 0, lf = Last[fr]; If[lf <= r, r = r - lf; PrependTo[s, lf]]; fr = Drop[fr, -1]]; s]; Select[ Range[400], Length[z[#]] == 2 &] (* Jean-François Alcover, Sep 27 2011 *)
    zeck = DigitCount[Select[Range[5000], BitAnd[#, 2*#] == 0&], 2, 1];
    Position[zeck, 2] // Flatten (* Jean-François Alcover, Jan 25 2018 *)
  • Python
    from math import comb, isqrt
    from sympy import fibonacci
    def A179242(n): return fibonacci((m:=isqrt(n<<3)+1>>1)+3)+fibonacci(n+1-comb(m, 2)) # Chai Wah Wu, Apr 09 2025

A179253 Numbers k that have 13 terms in their Zeckendorf representation.

Original entry on oeis.org

196417, 271442, 300099, 311045, 315226, 316823, 317433, 317666, 317755, 317789, 317802, 317807, 317809, 317810, 392835, 421492, 432438, 436619, 438216, 438826, 439059, 439148, 439182, 439195, 439200, 439202, 439203, 467860, 478806, 482987
Offset: 1

Views

Author

Emeric Deutsch, Jul 05 2010

Keywords

Comments

A007895(a(n)) = 13. - Reinhard Zumkeller, Mar 10 2013

Examples

			196417 = 1 + 3 + 8 + 21 + 55 + 144 + 377 + 987 + 2584 + 6765 + 17711 + 46368 + 121393;
271442 = 1 + 3 + 8 + 21 + 55 + 144 + 377 + 987 + 2584 + 6765 + 17711 + 46368 + 196418;
		

Crossrefs

Programs

  • Haskell
    a179253 n = a179253_list !! (n-1)
    a179253_list = filter ((== 13) . a007895) [1..]
    -- Reinhard Zumkeller, Mar 10 2013
  • Maple
    with(combinat): seq(add(fibonacci(2*k), k = 1 .. 13-m)+add(fibonacci(27-2*k+2), k = 1 .. m), m = 0 .. 13); # this program yields only the first 14 terms of the sequence
    From R. J. Mathar, Jul 23 2010: (Start)
    Lzto10 := proc(L) local i ; add( op(i,L)*combinat[fibonacci](i+1),i=1..nops(L) ) ; end proc:
    zbits := proc(numbits,toset,upbits) local L,hibi ; if 2*toset-1 > numbits then return ; end if; if toset = 0 then L := [(seq(0,i=1..numbits)),op(upbits)] ; Lzto10(L); print(%) ; else for hibi from toset-1 to numbits -1 do if toset = 1 then procname(hibi,toset-1,[1,seq(0,i=1..numbits-hibi-1),op(upbits)]) ; else procname(hibi-1,toset-1,[0,1,seq(0,i=1..numbits-hibi-1),op(upbits)]) ; end if; end do; end if; return ; end proc:
    ztot := 13 : for numbits from 2*ztot -1 to 50 do zbits(numbits-2,ztot-1,[0,1]) ; end do: (End)
  • Mathematica
    Reap[For[m = 0; k = 1, k <= 10^8, k++, If[BitAnd[k, 2 k] == 0, m++; If[DigitCount[k, 2, 1] == 13, Print[m]; Sow[m]]]]][[2, 1]] (* Jean-François Alcover, Aug 20 2023 *)

Extensions

More terms from R. J. Mathar, Jul 23 2010

A179245 Numbers that have 5 terms in their Zeckendorf representation.

Original entry on oeis.org

88, 122, 135, 140, 142, 143, 177, 190, 195, 197, 198, 211, 216, 218, 219, 224, 226, 227, 229, 230, 231, 266, 279, 284, 286, 287, 300, 305, 307, 308, 313, 315, 316, 318, 319, 320, 334, 339, 341, 342, 347, 349, 350, 352, 353, 354, 360, 362, 363, 365, 366, 367
Offset: 1

Views

Author

Emeric Deutsch, Jul 05 2010

Keywords

Comments

A007895(a(n)) = 5. - Reinhard Zumkeller, Mar 10 2013
Numbers that are the sum of five non-consecutive Fibonacci numbers. Their Zeckendorf representation thus consists of five 1's with at least one 0 between each pair of 1's; for example, 122 is represented as 1001010101. - Alonso del Arte, Nov 17 2013

Examples

			88  = 55 + 21 + 8 + 3 + 1.
122 = 89 + 21 + 8 + 3 + 1.
135 = 89 + 34 + 8 + 3 + 1.
140 = 89 + 34 + 13 + 3 + 1.
142 = 89 + 34 + 13 + 5 + 1.
81 is not in the sequence because, although it is the sum of five Fibonacci numbers (81 = 5 + 8 + 13 + 21 + 34), its Zeckendorf representation only has three terms: 81 = 55 + 21 + 5.
		

Crossrefs

Cf. A035517, A007895. Numbers that have m terms in their Zeckendorf representations: A179242 (m = 2), A179243 (m = 3), A179244 (m = 4), A179246 (m = 6), A179247 (m = 7), A179248 (m = 8), A179249 (m = 9), A179250 (m = 10), A179251 (m = 11), A179252 (m = 12), A179253 (m = 13).

Programs

  • Haskell
    a179245 n = a179245_list !! (n-1)
    a179245_list = filter ((== 5) . a007895) [1..]
    -- Reinhard Zumkeller, Mar 10 2013
    
  • Maple
    with(combinat): B := proc (n) local A, ct, m, j: A := proc (n) local i: for i while fibonacci(i) <= n do n-fibonacci(i) end do end proc: ct := 0: m := n: for j while 0 < A(m) do ct := ct+1: m := A(m) end do: ct+1 end proc: Q := {}: for i from fibonacci(11)-1 to 400 do if B(i) = 5 then Q := `union`(Q, {i}) else end if end do: Q;
  • Mathematica
    zeck = DigitCount[Select[Range[3000], BitAnd[#, 2*#] == 0 &], 2, 1];
    Position[zeck, 5] // Flatten (* Jean-François Alcover, Jan 30 2018 *)
  • PARI
    A048680(n)=my(k=1,s);while(n,if(n%2,s+=fibonacci(k++)); k++; n>>=1); s
    [A048680(n)|n<-[1..100],hammingweight(n)==5] \\ Charles R Greathouse IV, Nov 17 2013

Formula

a(n) = A048680(A014313(n)). - Charles R Greathouse IV, Nov 17 2013

A179246 Numbers that have 6 terms in their Zeckendorf representation.

Original entry on oeis.org

232, 321, 355, 368, 373, 375, 376, 465, 499, 512, 517, 519, 520, 554, 567, 572, 574, 575, 588, 593, 595, 596, 601, 603, 604, 606, 607, 608, 698, 732, 745, 750, 752, 753, 787, 800, 805, 807, 808, 821, 826, 828, 829, 834, 836, 837, 839, 840, 841, 876, 889
Offset: 1

Views

Author

Emeric Deutsch, Jul 05 2010

Keywords

Comments

A007895(a(n)) = 6. - Reinhard Zumkeller, Mar 10 2013

Examples

			232 = 144 + 55 + 21 +  8 + 3 + 1;
321 = 233 + 55 + 21 +  8 + 3 + 1;
355 = 233 + 89 + 21 +  8 + 3 + 1;
368 = 233 + 89 + 34 +  8 + 3 + 1;
373 = 233 + 89 + 34 + 13 + 3 + 1.
		

Crossrefs

Programs

  • Haskell
    a179246 n = a179246_list !! (n-1)
    a179246_list = filter ((== 6) . a007895) [1..]
    -- Reinhard Zumkeller, Mar 10 2013
  • Maple
    with(combinat): B := proc (n) local A, ct, m, j: A := proc (n) local i; for i while fibonacci(i) <= n do n-fibonacci(i) end do end proc: ct := 0: m := n: for j while 0 < A(m) do ct := ct+1: m := A(m) end do: ct+1 end proc: Q := {}: for i from fibonacci(13)-1 to 900 do if B(i) = 6 then Q := `union`(Q, {i}) else end if end do: Q;
  • Mathematica
    zeck = DigitCount[Select[Range[12000], BitAnd[#, 2*#] == 0 &], 2, 1];
    Position[zeck, 6] // Flatten (* Jean-François Alcover, Jan 30 2018 *)

A179247 Numbers that have 7 terms in their Zeckendorf representation.

Original entry on oeis.org

609, 842, 931, 965, 978, 983, 985, 986, 1219, 1308, 1342, 1355, 1360, 1362, 1363, 1452, 1486, 1499, 1504, 1506, 1507, 1541, 1554, 1559, 1561, 1562, 1575, 1580, 1582, 1583, 1588, 1590, 1591, 1593, 1594, 1595, 1829, 1918, 1952, 1965, 1970, 1972, 1973
Offset: 1

Views

Author

Emeric Deutsch, Jul 05 2010

Keywords

Comments

A007895(a(n)) = 7. - Reinhard Zumkeller, Mar 10 2013

Examples

			609 = 377+144+55+21+8+3+1;
842 = 610+144+55+21+8+3+1;
931 = 610+233+55+21+8+3+1;
965 = 610+233+89+21+8+3+1;
978 = 610+233+89+34+8+3+1.
		

Crossrefs

Programs

  • Haskell
    a179247 n = a179247_list !! (n-1)
    a179247_list = filter ((== 7) . a007895) [1..]
    -- Reinhard Zumkeller, Mar 10 2013
  • Maple
    with(combinat): B := proc (n) local A, ct, m, j: A := proc (n) local i: for i while fibonacci(i) <= n do n-fibonacci(i) end do end proc: ct := 0: m := n: for j while 0 < A(m) do ct := ct+1: m := A(m) end do: ct+1 end proc: Q := {}: for i from fibonacci(15)-1 to 2100 do if B(i) = 7 then Q := `union`(Q, {i}) else end if end do: Q;
  • Mathematica
    zeck = DigitCount[Select[Range[4*10^4], BitAnd[#, 2*#] == 0 &], 2, 1];
    Position[zeck, 7] // Flatten (* Jean-François Alcover, Jan 30 2018 *)

A179248 Numbers that have 8 terms in their Zeckendorf representation.

Original entry on oeis.org

1596, 2206, 2439, 2528, 2562, 2575, 2580, 2582, 2583, 3193, 3426, 3515, 3549, 3562, 3567, 3569, 3570, 3803, 3892, 3926, 3939, 3944, 3946, 3947, 4036, 4070, 4083, 4088, 4090, 4091, 4125, 4138, 4143, 4145, 4146, 4159, 4164, 4166, 4167, 4172, 4174, 4175
Offset: 1

Views

Author

Emeric Deutsch, Jul 05 2010

Keywords

Comments

A007895(a(n)) = 8. - Reinhard Zumkeller, Mar 10 2013

Examples

			1596 =  987+377+144+55+21+8+3+1;
2206 = 1597+377+144+55+21+8+3+1;
2439 = 1597+610+144+55+21+8+3+1;
2528 = 1597+610+233+55+21+8+3+1;
2562 = 1597+610+233+89+21+8+3+1.
		

Crossrefs

Programs

  • Haskell
    a179249 n = a179249_list !! (n-1)
    a179249_list = filter ((== 9) . a007895) [1..]
    -- Reinhard Zumkeller, Mar 10 2013
  • Maple
    with(combinat): B := proc (n) local A, ct, m, j: A := proc (n) local i: for i while fibonacci(i) <= n do n-fibonacci(i) end do end proc: ct := 0: m := n: for j while 0 < A(m) do ct := ct+1: m := A(m) end do: ct+1 end proc: Q := {}: for i from fibonacci(17)-1 to 5000 do if B(i) = 8 then Q := `union`(Q, {i}) else end if end do: Q;
  • Mathematica
    zeck = DigitCount[Select[Range[10^5], BitAnd[#, 2*#] == 0 &], 2, 1];
    Position[zeck, 8] // Flatten (* Jean-François Alcover, Jan 30 2018 *)

A179249 Numbers that have 9 terms in their Zeckendorf representation.

Original entry on oeis.org

4180, 5777, 6387, 6620, 6709, 6743, 6756, 6761, 6763, 6764, 8361, 8971, 9204, 9293, 9327, 9340, 9345, 9347, 9348, 9958, 10191, 10280, 10314, 10327, 10332, 10334, 10335, 10568, 10657, 10691, 10704, 10709, 10711, 10712, 10801, 10835, 10848
Offset: 1

Views

Author

Emeric Deutsch, Jul 05 2010

Keywords

Comments

A007895(a(n)) = 9. - Reinhard Zumkeller, Mar 10 2013

Examples

			4180 = 2584 +987+377+144+55+21+8+3+1;
5777 = 4181 +987+377+144+55+21+8+3+1;
6387 = 4181+1597+377+144+55+21+8+3+1;
6620 = 4181+1597+610+144+55+21+8+3+1;
6709 = 4181+1597+610+233+55+21+8+3+1.
		

Crossrefs

Programs

  • Haskell
    a179249 n = a179249_list !! (n-1)
    a179249_list = filter ((== 9) . a007895) [1..]
    -- Reinhard Zumkeller, Mar 10 2013
  • Maple
    with(combinat): B := proc (n) local A, ct, m, j: A := proc (n) local i: for i while fibonacci(i) <= n do n-fibonacci(i) end do end proc: ct := 0: m := n: for j while 0 < A(m) do ct := ct+1: m := A(m) end do: ct+1 end proc: Q := {}: for i from fibonacci(19)-1 to 10900 do if B(i) = 9 then Q := `union`(Q, {i}) else end if end do: Q;
  • Mathematica
    zeck = DigitCount[Select[Range[4*10^5], BitAnd[#, 2*#] == 0 &], 2, 1];
    Position[zeck, 9] // Flatten (* Jean-François Alcover, Jan 30 2018 *)

A179250 Numbers that have 10 terms in their Zeckendorf representation.

Original entry on oeis.org

10945, 15126, 16723, 17333, 17566, 17655, 17689, 17702, 17707, 17709, 17710, 21891, 23488, 24098, 24331, 24420, 24454, 24467, 24472, 24474, 24475, 26072, 26682, 26915, 27004, 27038, 27051, 27056, 27058, 27059, 27669, 27902, 27991
Offset: 1

Views

Author

Emeric Deutsch, Jul 05 2010

Keywords

Comments

A007895(a(n)) = 10. - Reinhard Zumkeller, Mar 10 2013

Examples

			10945=6765+2584+987+377+144+55+21+8+3+1;
15126=10946+2584+987+377+144+55+21+8+3+1;
16723=10946+4181+987+377+144+55+21+8+3+1;
		

Crossrefs

Programs

  • Haskell
    a179250 n = a179250_list !! (n-1)
    a179250_list = filter ((== 10) . a007895) [1..]
    -- Reinhard Zumkeller, Mar 10 2013
  • Maple
    with(combinat): B := proc (n) local A, ct, m, j: A := proc (n) local i: for i while fibonacci(i) <= n do n-fibonacci(i) end do end proc: ct := 0: m := n: for j while 0 < A(m) do ct := ct+1: m := A(m) end do: ct+1 end proc: Q := {}: for i from fibonacci(21)-1 to 28500 do if B(i) = 10 then Q := `union`(Q, {i}) else end if end do: Q;
  • Mathematica
    zeck = DigitCount[Select[Range[2*10^6], BitAnd[#, 2*#] == 0 &], 2, 1];
    Position[zeck, 10] // Flatten (* Jean-François Alcover, Jan 30 2018 *)

A179251 Numbers that have 11 terms in their Zeckendorf representation.

Original entry on oeis.org

28656, 39602, 43783, 45380, 45990, 46223, 46312, 46346, 46359, 46364, 46366, 46367, 57313, 61494, 63091, 63701, 63934, 64023, 64057, 64070, 64075, 64077, 64078, 68259, 69856, 70466, 70699, 70788, 70822, 70835, 70840, 70842, 70843
Offset: 1

Views

Author

Emeric Deutsch, Jul 05 2010

Keywords

Comments

A007895(a(n)) = 11. - Reinhard Zumkeller, Mar 10 2013

Examples

			28656=17711+6765+2584+987+377+144+55+21+8+3+1;
39602=28657+6765+2584+987+377+144+55+21+8+3+1;
		

Crossrefs

Programs

  • Haskell
    a179251 n = a179251_list !! (n-1)
    a179251_list = filter ((== 11) . a007895) [1..]
    -- Reinhard Zumkeller, Mar 10 2013
  • Maple
    with(combinat): B := proc (n) local A, ct, m, j: A := proc (n) local i: for i while fibonacci(i) <= n do n-fibonacci(i) end do end proc: ct := 0: m := n: for j while 0 < A(m) do ct := ct+1: m := A(m) end do: ct+1 end proc: Q := {}: for i from fibonacci(23)-1 to 73000 do if B(i) = 11 then Q := `union`(Q, {i}) else end if end do: Q;
  • Mathematica
    Select[Range[6*10^6], BitAnd[#, 2*#] == 0&] // DigitCount[#, 2, 1]& // Position[#, 11]& // Flatten (* Jean-François Alcover, Feb 15 2018 *)
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