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 1-3 of 3 results.

A110737 Row sums in A112668.

Original entry on oeis.org

1, 4, 21, 40, 1555, 3906, 299593, 3280, 87381, 435848050, 67546215517, 61035156, 61054982558011, 328114698808274, 76861433640456465, 21523360, 128583032925805678351, 953674316406, 275941052631578947368421, 1743392200
Offset: 1

Views

Author

Amarnath Murthy, Aug 10 2005

Keywords

Comments

For all n, a(n) is a term in row n of triangle A125118, and furthermore if n is prime then a(n) = A060072(n+1). - Mathew Englander, Dec 20 2020

Links

Crossrefs

Cf. A110738, A110739, A125118, A060072.

Programs

  • Maple
    A110737 := proc(n) local i,a ; if n = 1 then RETURN(1) ; else a := 2 ; while (1-a^n)/(1-a) mod n <> 0 do a := a+1 ; od ; RETURN( (1-a^n)/(1-a) ) ; fi ; end: for n from 1 to 25 do printf("%d, ",A110737(n)) : od : # R. J. Mathar, Mar 13 2007
  • Mathematica
    Block[{a = {1}, k, s}, Do[k = 2; While[Mod[Set[s, Total@ NestList[# k &, 1, i - 1]], i] != 0, k++]; AppendTo[a, s], {i, 2, 20}]; a] (* Michael De Vlieger, Dec 31 2020 *)

Extensions

More terms from R. J. Mathar, Mar 13 2007

A110738 a(n) = common ratio for row n in A112668.

Original entry on oeis.org

1, 3, 4, 3, 6, 5, 8, 3, 4, 9, 12, 5, 14, 13, 16, 3, 18, 5, 20, 3, 4, 21, 24, 5, 6, 25, 4, 13, 30, 11, 32, 3, 34, 33, 36, 5, 38, 37, 16, 3, 42, 5, 44, 21, 16, 45, 48, 5, 8, 9, 52, 5, 54, 5, 16, 13, 7, 57, 60, 7, 62, 61, 4, 3, 66, 23, 68, 13, 70, 29, 72, 5, 74, 73, 16, 37, 78, 17, 80, 3
Offset: 1

Views

Author

Amarnath Murthy, Aug 10 2005

Keywords

Crossrefs

Cf. A110737, A110739.
Cf. A074792, A083503.

Programs

  • Maple
    A110738 := proc(n) local a ; if n = 1 then RETURN(1) ; else a := 2 ; while (1-a^n)/(1-a) mod n <> 0 do a := a+1 ; od ; RETURN(a) ; fi ; end: for n from 1 to 80 do printf("%d, ",A110738(n)) : od : # R. J. Mathar, Mar 13 2007

Extensions

More terms from R. J. Mathar, Mar 13 2007

A112668 Triangle read by rows: row n gives an n-term geometric progression with first term 1 such that the sum of the n terms is a multiple of n.

Original entry on oeis.org

1, 1, 3, 1, 4, 16, 1, 3, 9, 27, 1, 6, 36, 216, 1296, 1, 5, 25, 125, 625, 3125, 1, 8, 64, 512, 4096, 32768, 262144, 1, 3, 9, 27, 81, 243, 729, 2187, 1, 4, 16, 64, 256, 1024, 4096, 16384, 65536, 1, 9, 81, 729, 6561, 59049, 531441, 4782969, 43046721, 387420489, 1
Offset: 1

Views

Author

Amarnath Murthy, Aug 10 2005

Keywords

Examples

			1
1 3
1 4 16
1 3 9 27
1 6 36 216 1296
1 5 25 125 625 3125
...

Links

Crossrefs

Cf. A110737, A110738, A110739.

Programs

  • Maple
    A112668 := proc(n) local a2,i,a ; a2 := 2 ; while (1-a2^n)/(1-a2) mod n <> 0 do a2 := a2+1 ; od ; a := [] ; for i from 1 to n do a := [op(a), a2^(i-1)] ; od ; RETURN(a) ; end: for row from 1 to 14 do r := A112668(row) : for n from 1 to nops(r) do printf("%d, ",op(n,r)) ; od : od : # R. J. Mathar, Mar 13 2007
  • Mathematica
    Block[{a = {{1}}, k, s}, Do[k = 2; While[Mod[Total@ Set[s, NestList[# k &, 1, i - 1]], i] != 0, k++]; AppendTo[a, s], {i, 2, 10}]; a] // Flatten (* Michael De Vlieger, Dec 31 2020 *)

Extensions

More terms from R. J. Mathar, Mar 13 2007
Showing 1-3 of 3 results.

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