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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A299763 a(n) = 1 + A182986(n).

Original entry on oeis.org

1, 3, 4, 6, 8, 12, 14, 18, 20, 24, 30, 32, 38, 42, 44, 48, 54, 60, 62, 68, 72, 74, 80, 84, 90, 98, 102, 104, 108, 110, 114, 128, 132, 138, 140, 150, 152, 158, 164, 168, 174, 180, 182, 192, 194, 198, 200, 212, 224, 228, 230, 234, 240, 242, 252, 258, 264, 270, 272, 278, 282, 284
Offset: 1

Views

Author

Omar E. Pol, Mar 14 2018

Keywords

Comments

Are these the indices of the rows of A299762 where there is a record?

Crossrefs

First differences are in A054541.
Essentially the same as A008864, A028815, A055670, A135731, A175216.

Programs

Formula

a(n) = A028815(n-1) - [n=1].
a(n) = A008864(n-1) for n >= 2, with a(1) = 1.

A309633 G.f.: x * Sum_{k>=1} x^k / (1 - a(k)*x^k).

Original entry on oeis.org

0, 1, 1, 1, 2, 1, 3, 1, 3, 2, 4, 1, 5, 1, 5, 6, 4, 1, 7, 1, 13, 11, 6, 1, 7, 17, 7, 11, 31, 1, 45, 1, 10, 18, 6, 146, 34, 1, 9, 27, 141, 1, 261, 1, 78, 364, 8, 1, 44, 730, 537, 18, 145, 1, 255, 1281, 2203, 51, 33, 1, 2213, 1, 47, 7461, 221, 4722, 1159, 1, 85, 38, 27948, 1, 2342, 1, 36, 17060, 347, 63146, 3427, 1
Offset: 1

Views

Author

Ilya Gutkovskiy, Aug 10 2019

Keywords

Crossrefs

Cf. A028815 (positions of 1's), A087909, A127525, A309634.

Programs

  • Mathematica
    a[n_] := a[n] = SeriesCoefficient[x Sum[x^k/(1 - a[k] x^k), {k, 1, n - 1}], {x, 0, n}]; Table[a[n], {n, 1, 80}]
    a[n_] := a[n] = Sum[a[d]^((n - 1)/d - 1) , {d, Divisors[n - 1]}]; a[1] = 0; a[2] = 1; Table[a[n], {n, 1, 80}]
  • PARI
    seq(n)={my(v=vector(n)); for(n=1, #v-1, v[n+1]=sumdiv(n, d, v[d]^(n/d-1))); v} \\ Andrew Howroyd, Aug 10 2019

Formula

a(1) = 0; a(n+1) = Sum_{d|n} a(d)^(n/d-1).

A309634 G.f.: x * Sum_{k>=1} x^k / (1 - x^k)^a(k).

Original entry on oeis.org

0, 1, 1, 1, 2, 1, 3, 1, 3, 2, 4, 1, 5, 1, 5, 5, 4, 1, 7, 1, 9, 8, 6, 1, 7, 6, 7, 8, 14, 1, 18, 1, 9, 12, 6, 23, 17, 1, 9, 17, 17, 1, 35, 1, 31, 41, 8, 1, 23, 29, 24, 12, 44, 1, 33, 47, 49, 30, 16, 1, 61, 1, 20, 120, 40, 84, 105, 1, 35, 23, 85, 1, 68, 1, 19, 115, 88, 151, 160, 1
Offset: 1

Views

Author

Ilya Gutkovskiy, Aug 10 2019

Keywords

Crossrefs

Cf. A028815 (positions of 1's), A157019, A309633.

Programs

  • Maple
    a:= proc(n) option remember; uses numtheory;
          add(binomial((n-1)/d+a(d)-2, a(d)-1), d=divisors(n-1))
        end:
    seq(a(n), n=1..80);  # Alois P. Heinz, Jan 27 2025
  • Mathematica
    a[n_] := a[n] = SeriesCoefficient[x Sum[x^k/(1 - x^k)^a[k], {k, 1, n - 1}], {x, 0, n}]; Table[a[n], {n, 1, 80}]
    a[n_] := a[n] = Sum[Binomial[(n - 1)/d + a[d] - 2, a[d] - 1], {d, Divisors[n - 1]}]; a[1] = 0; Table[a[n], {n, 1, 80}]
  • PARI
    seq(n)={my(v=vector(n)); v[2]=1; for(n=2, #v-1, v[n+1] = sumdiv(n, d, binomial(n/d + v[d] - 2, v[d] - 1))); v} \\ Andrew Howroyd, Aug 10 2019

Formula

a(1) = 0; a(n+1) = Sum_{d|n} binomial(n/d+a(d)-2,a(d)-1).
Previous Showing 11-13 of 13 results.