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.

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A127950 a(n) = A007376(8*n+2).

Original entry on oeis.org

2, 1, 1, 1, 2, 2, 3, 3, 3, 4, 4, 5, 5, 5, 6, 6, 7, 7, 7, 8, 8, 9, 9, 9, 0, 1, 6, 0, 1, 4, 1, 1, 2, 2, 1, 0, 3, 1, 8, 4, 1, 6, 4, 1, 4, 5, 1, 2, 6, 1, 0, 7, 1, 8, 8, 1, 6, 8, 1, 4, 9, 2, 2, 0, 2, 0, 1, 2, 8, 2, 2, 6, 2, 2, 4, 3, 2, 2, 4, 2, 0, 5, 2, 8, 6, 2, 6, 6, 2, 4, 7, 2, 2, 8, 2, 0, 9, 2, 8, 0, 3, 6, 0, 3, 4
Offset: 0

Views

Author

N. J. A. Sloane, Jul 23 2008

Keywords

Crossrefs

Cf. A007376.

Programs

  • Mathematica
    A007376 := Flatten[IntegerDigits /@ Range[1600]]; Table[A007376[[8*n + 2]], {n, 0, 100}] (* G. C. Greubel, May 05 2018 *)
  • Python
    from itertools import islice, count
    def A127950gen(): return islice((int(d) for n in count(0) for d in str(n)),2,None,8)
    A127950_list = list(islice(A127950gen(),40)) # Chai Wah Wu, Dec 04 2021

A128475 A007376(8n+7).

Original entry on oeis.org

7, 2, 6, 0, 4, 8, 2, 6, 0, 4, 8, 2, 6, 0, 4, 8, 2, 6, 0, 4, 8, 2, 6, 0, 1, 5, 0, 1, 3, 1, 1, 1, 2, 1, 9, 3, 1, 7, 4, 1, 5, 4, 1, 3, 5, 1, 1, 6, 1, 9, 7, 1, 7, 8, 1, 5, 8, 1, 3, 9, 1, 1, 0, 2, 9, 1, 2, 7, 2, 2, 5, 2, 2, 3, 3, 2, 1, 4, 2, 9, 5, 2, 7, 6, 2, 5, 6, 2, 3, 7, 2, 1, 8, 2, 9, 9, 2, 7, 0, 3, 5, 0, 3, 3, 1
Offset: 0

Views

Author

N. J. A. Sloane, Jul 23 2008

Keywords

A254649 a(1) = A007376(1) = 1, n > 1: a(n) = smallest number not occurring earlier, that is the sum of unused next consecutive terms of A007376.

Original entry on oeis.org

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 15, 19, 14, 13, 17, 12, 16, 18, 20, 21, 22, 26, 25, 31, 30, 28, 27, 36, 33, 43, 24, 39, 29, 32, 34, 35, 23, 45, 41, 40, 37, 44, 46, 38, 47, 48, 51, 52, 50, 57, 58, 42, 59, 55, 53, 60, 49, 56, 54, 61, 63, 65, 62, 64, 66, 72
Offset: 1

Views

Author

Reinhard Zumkeller, Feb 04 2015

Keywords

Comments

A permutation of the positive integers with inverse A254650.

Examples

			.     n |1|2|3|4|5|6|7|8|9|10             |11     |12     |13     |14
.  a(n) |1|2|3|4|5|6|7|8|9|           10  |    11 |    15 |    19 |     14
--------+-+-+-+-+-+-+-+-+-+---------------+-------+-------+-------+--------
A007376 |1|2|3|4|5|6|7|8|9|1+0+1+1+1+2+1+3|1+4+1+5|1+6+1+7|1+8+1+9|2+0+2....
-
		

Crossrefs

Cf. A007376, A033307, A254650 (inverse), A254656 (fixed points).

Programs

  • Haskell
    a254649 n = a254649_list !! (n-1)
    a254649_list = f a007376_list [0] where
       f (x:xs) ys = g x xs where
         g y zs'@(z:zs) | y `elem` ys = g (y + z) zs
                        | otherwise   = y : f zs' (y:ys)

A098728 Consider the sequence {b(n), n >= 1} of digits of the natural (or counting) numbers: 1 2 3 4 5 6 7 8 9 1 0 1 1 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 0... (A007376); a(n) = n - b(n).

Original entry on oeis.org

0, 0, 0, 0, 0, 0, 0, 0, 0, 9, 11, 11, 12, 13, 13, 15, 14, 17, 15, 19, 16, 21, 17, 23, 18, 25, 19, 27, 20, 28, 31, 30, 32, 32, 33, 34, 34, 36, 35, 38, 36, 40, 37, 42, 38, 44, 39, 46, 40, 47, 51, 49, 52, 51, 53, 53, 54, 55, 55, 57, 56, 59, 57, 61, 58, 63, 59, 65, 60, 66, 71, 68, 72
Offset: 0

Views

Author

Alexandre Wajnberg, Sep 30 2004

Keywords

Comments

Subtract each digit of the counting numbers from its rank.

Examples

			The sequence of digits of the counting numbers is
1 2 3 4 5 6 7 8 9 1 0 1 1 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 0...
The 15th term, for instance, is a 2. Thus 15-2=13 is the 15th term of this sequence.
Next one is a 1, thus 16 (the rank) - 1 (the 16th digit of the decimal expansion of the counting numbers) = 15, which is the 16th term of this sequence.
Next one is 17-3=14
		

Programs

  • Mathematica
    With[{c=Flatten[IntegerDigits/@Range[70]]},#[[1]]-#[[2]]&/@Partition[ Riffle[ Range[Length[c]],c],2]] (* Harvey P. Dale, Aug 07 2019 *)

Extensions

More terms from Stacy Hawthorne (shawtho1(AT)ashland.edu), Jan 12 2006

A119385 Write out the digits of the integers in order (cf. A007376): 0 1 2 3 4 5 6 7 8 9 1 0 1 1 1 2 1 3 1 4 1 5 ...; a(n) = sum of digits between successive zeros.

Original entry on oeis.org

0, 46, 56, 66, 76, 86, 96, 106, 116, 126, 127, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 66, 76, 86, 96, 106, 116, 126, 136, 137, 0, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 76, 86, 96, 106, 116, 126, 136, 146, 147, 0, 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 86, 96, 106, 116, 126, 136, 146, 156, 157, 0, 4
Offset: 0

Views

Author

N. J. A. Sloane, Jul 26 2006

Keywords

Comments

a(0) = 0 by convention.

Programs

  • Maple
    c:=proc(x,y) local s: s:=proc(m) nops(convert(m,base,10)) end: if y=0 then 10*x else x*10^s(y)+y: fi end: b:=proc(n) local nn: nn:=convert(n,base,10): [seq(nn[nops(nn)+1-i],i=1..nops(nn))] end: A:=0: for n from 1 to 500 do A:=c(A,n) od: B:=[0,seq(b(A)[j],j=1..nops(b(A)))]: u:=proc(n) if B[n]=0 then n else fi end: U:=[seq(u(n),n=1..nops(B))]: 0,seq(add(B[j],j=U[i]..U[i+1]),i=1..nops(U)-1); # there must exist a simpler Maple program! - Emeric Deutsch, Jul 27 2006
    #alternative
    A119385 := proc(n) option remember ; local nupto,a,a007376,k ; if n =0 then RETURN([0,0]) ; else nupto := op(2,A119385(n-1)) ; a := 0 ; for k from nupto+1 do a007376 := A007376(k) ; if op(1,a007376) > 0 then a := a+op(1,a007376) ; else RETURN([a,k]) ; fi ; od: fi ; end :# R. J. Mathar, Jan 21 2008
  • Mathematica
    list1=Flatten[Table[IntegerDigits[i],{i,0,1000}]];
    index1=Partition[Flatten[Position[list1,0]],2,1];
    Plus@@@Table[Take[list1,Flatten[Take[index1,{i}]]],{i,Length[index1]}] (From Harvey Dale)

Extensions

More terms from Emeric Deutsch, Jul 27 2006

A127414 a(n) = A007376(4*n+1).

Original entry on oeis.org

1, 5, 9, 1, 3, 5, 7, 9, 1, 3, 5, 7, 9, 1, 3, 5, 7, 9, 1, 3, 5, 7, 9, 1, 3, 5, 7, 9, 1, 3, 5, 7, 9, 1, 3, 5, 7, 9, 1, 3, 5, 7, 9, 1, 3, 5, 7, 9, 1, 0, 3, 1, 0, 7, 1, 1, 1, 1, 1, 5, 1, 1, 9, 1, 2, 3, 1, 2, 7, 1, 3, 1, 1, 3, 5, 1, 3, 9, 1, 4, 3, 1, 4, 7, 1, 5, 1, 1, 5, 5, 1, 5, 9, 1, 6, 3, 1, 6, 7, 1, 7, 1, 1, 7, 5
Offset: 0

Views

Author

N. J. A. Sloane, Jul 23 2008

Keywords

Programs

A127508 A007376(4n+2).

Original entry on oeis.org

2, 6, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 6, 6, 6, 6, 6, 7, 7, 7, 7, 7, 8, 8, 8, 8, 8, 9, 9, 9, 9, 9, 1, 0, 2, 1, 0, 6, 1, 0, 0, 1, 1, 4, 1, 1, 8, 1, 2, 2, 1, 2, 6, 1, 2, 0, 1, 3, 4, 1, 3, 8, 1, 4, 2, 1, 4, 6, 1, 4, 0, 1, 5, 4, 1, 5, 8, 1, 6, 2, 1, 6, 6, 1, 6, 0, 1, 7, 4, 1
Offset: 0

Views

Author

N. J. A. Sloane, Jul 23 2008

Keywords

A127584 A007376(4n+3).

Original entry on oeis.org

3, 7, 0, 2, 4, 6, 8, 0, 2, 4, 6, 8, 0, 2, 4, 6, 8, 0, 2, 4, 6, 8, 0, 2, 4, 6, 8, 0, 2, 4, 6, 8, 0, 2, 4, 6, 8, 0, 2, 4, 6, 8, 0, 2, 4, 6, 8, 0, 1, 1, 0, 5, 1, 0, 9, 1, 1, 3, 1, 1, 7, 1, 2, 1, 1, 2, 5, 1, 2, 9, 1, 3, 3, 1, 3, 7, 1, 4, 1, 1, 4, 5, 1, 4, 9, 1, 5, 3, 1, 5, 7, 1, 6, 1, 1, 6, 5, 1, 6, 9, 1, 7, 3, 1, 7
Offset: 0

Views

Author

N. J. A. Sloane, Jul 23 2008

Keywords

A127734 A007376(4n).

Original entry on oeis.org

4, 8, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 6, 6, 6, 6, 6, 7, 7, 7, 7, 7, 8, 8, 8, 8, 8, 9, 9, 9, 9, 9, 0, 1, 0, 4, 1, 0, 8, 1, 1, 2, 1, 1, 6, 1, 1, 0, 1, 2, 4, 1, 2, 8, 1, 3, 2, 1, 3, 6, 1, 3, 0, 1, 4, 4, 1, 4, 8, 1, 5, 2, 1, 5, 6, 1, 5, 0, 1, 6, 4, 1, 6, 8, 1, 7, 2, 1, 7, 6
Offset: 1

Views

Author

N. J. A. Sloane, Jul 23 2008

Keywords

A127794 A007376(8n+1).

Original entry on oeis.org

1, 9, 3, 7, 1, 5, 9, 3, 7, 1, 5, 9, 3, 7, 1, 5, 9, 3, 7, 1, 5, 9, 3, 7, 1, 3, 0, 1, 1, 1, 1, 9, 2, 1, 7, 3, 1, 5, 3, 1, 3, 4, 1, 1, 5, 1, 9, 6, 1, 7, 7, 1, 5, 7, 1, 3, 8, 1, 1, 9, 1, 9, 0, 2, 7, 1, 2, 5, 1, 2, 3, 2, 2, 1, 3, 2, 9, 4, 2, 7, 5, 2, 5, 5, 2, 3, 6, 2, 1, 7, 2, 9, 8, 2, 7, 9, 2, 5, 9, 3, 3, 0, 3, 1, 1
Offset: 0

Views

Author

N. J. A. Sloane, Jul 23 2008

Keywords

Previous Showing 21-30 of 133 results. Next