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.

A112284 A112283/n.

Original entry on oeis.org

1, 1, 1, 2, 1, 12, 1, 3, 1, 13, 1, 22, 1, 12, 14, 19, 1, 9, 1, 27, 18, 31, 1, 19, 1, 49, 1, 12, 1, 59, 1, 17, 61, 27, 15, 14, 1, 98, 6, 7, 1, 12, 1, 95, 45, 9, 1, 17, 1, 26, 73, 23, 1, 18, 10, 35, 69, 17, 1, 108, 1, 29, 65, 28, 47
Offset: 1

Views

Author

Keywords

Crossrefs

Programs

  • Mathematica
    f[n_] := Module[{j = 1, a}, a[0] = 1; a[l_] := a[l] = Block[{k = 1, s = Sum[ a[i]*x^i, {i, 0, l - 1}]}, While[ IntegerQ[ Last[ CoefficientList[ Series[(s + k*x^l)^(1/n), {x, 0, l}], x]]] != True, k++ ]; k]; While[a[j] != 1, j++ ]; j]; Table[ f[n]/n, {n, 10}]

Formula

Conjecture: a(n)=1 iff n is 1, a prime or the square of an odd prime.

Extensions

a(30)-a(50) from Robert G. Wilson v, Oct 29 2007
a(51)-a(65) from Robert G. Wilson v, Jul 25 2008

A141524 Consider the array T(n, m) where the n-th row is the sequence of integer coefficients of A(x), where 1<=a(n)<=n, such that A(x)^(1/n) consists entirely of integer coefficients and where m is the (m+1)-th coefficient. This is the table in the example of A112283 read term by term, row by row.

Original entry on oeis.org

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

Views

Author

Keywords

Examples

			1, 1,
1, 2, 1,
1, 3, 3, 1,
1, 4, 2, 4, 3, 4, 4, 4, 1,
1, 5, 5, 5, 5, 1,
1, 6, 3, 2, 3, 6, 6, 6, 3, 4, 6, 6, 6, 6, 3, 4, 6, 6, 3, 6, 6, 2, 3, 6, 6, 6, 3, 4, 6, 6, 2, 6, 6, 6, 6, 6, 6, 6, 3, 4, 6, 6, 4, 6, 6, 2, 6, 6, 4, 6, 3, 2, 3, 6, 6, 6, 3, 4, 3, 6, 3, 6, 3, 4, 6, 6, 2, 6, 3, 6, 3, 6, 1,
1, 7, 7, 7, 7, 7, 7, 1,
etc.
		

Crossrefs

Programs

  • Mathematica
    f[n_] := Module[{j = 1, a}, a[0] = 1; a[l_] := a[l] = Block[{k = 1, s = Sum[ a[i]*x^i, {i, 0, l - 1}]},While[ IntegerQ[ Last[ CoefficientList[ Series[(s + k*x^l)^(1/n), {x, 0, l}], x]]] != True, k++ ]; k]; While[a[j] != 1, j++ ]; Table[a[i], {i, 0, j}]]; Table[ f[n], {n, 65}] // Flatten

A112285 Consider the array T(n, m) where the n-th row is the sequence of integer coefficients of A(x), where 1<=a(n)<=n, such that A(x)^(1/n) consists entirely of integer coefficients and where m is the (m+1)-th coefficient. This is the row sum of A to the first coefficient of one.

Original entry on oeis.org

2, 4, 8, 27, 22, 340, 44, 156, 62, 1065, 112, 2467, 158, 1914, 2551, 4234, 274, 2161, 344, 8643, 6611, 12696, 508, 8410, 522, 28171, 566, 7500, 814, 39433, 932, 15000, 57160, 26980, 15681, 13590, 1334, 121327, 7786, 8908, 1642, 15896, 1808, 150069, 74267, 16105, 2164
Offset: 1

Views

Author

Keywords

Comments

mod(a(n),n):0,0,2,3,2,4,2,4,8,5,2,7,2,10,1,10,2,1,2,3,17,2,2,10,22,13,26,24,2, ...,.
The sum of just the even terms of T(n,k): 0,2,0,22,0,290,0,144,0,900,0,2288,0,1606,332,4124,0,1708,0,7908,790,10940,0,8196,0,24168,0,6920,0, ...,.

Crossrefs

Programs

  • Mathematica
    f[n_] := Module[{j = 1, a}, a[0] = 1; a[l_] := a[l] = Block[{k = 1, s = Sum[a[i]*x^i, {i, 0, l - 1}]}, While[ IntegerQ[ Last[ CoefficientList[ Series[(s + k*x^l)^(1/n), {x, 0, l}], x]]] != True, k++ ]; k]; While[a[j] != 1, j++ ]; Sum[ a[i], {i, 0, j}]]; Do[ Print[ f[n]], {n, 29}]

Formula

Sum_{m=0..k} from T(n, m), k is the least k>0 such that T(n, m)=1.
Sum_{m=0..A112283(n)} T(n, m).
a(p)=p(p-1)+2.

Extensions

More terms from Robert G. Wilson v, Jul 25 2008
Showing 1-3 of 3 results.