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.

Previous Showing 41-49 of 49 results.

A259155 Sum of all values v whose pi-based arithmetic derivative equals n.

Original entry on oeis.org

1, 2, 3, 5, 11, 11, 13, 23, 19, 23, 29, 41, 54, 41, 43, 61, 53, 59, 61, 82, 83, 95, 79, 83, 89, 123, 122, 103, 107, 109, 138, 161, 167, 155, 139, 187, 151, 190, 163, 167, 173, 260, 181, 191, 260, 197, 199, 211, 223, 285, 229, 233, 263, 333, 278, 308, 312, 269
Offset: 0

Views

Author

Alois P. Heinz, Jun 19 2015

Keywords

Crossrefs

Row sums of A259153.

Formula

a(n) = Sum_{v>=0, A258851(v)=n} v.
a(n) = Sum_{k=1..A259154(n)} A259153(n,k).
a(n) >= A000040(n) for n>0.

A259169 a(n) = n-th pi-based antiderivative of 8.

Original entry on oeis.org

8, 19, 15, 14, 43, 191, 201, 217, 1113, 1239, 986, 925, 375, 526, 689, 998, 3642, 3966, 5299, 4090, 7363, 20942, 150161, 117915, 218218, 597199, 472182, 494550, 1075362, 796042, 310086, 444985, 1403783, 1578955, 2702706, 10010173
Offset: 0

Views

Author

Alois P. Heinz, Jun 19 2015

Keywords

Examples

			a(7) = 217 -> 201 -> 191 -> 43 -> 14 -> 15 -> 19 -> 8.
a(8) = 1113 -> 1714 -> 1153 -> 191 -> 43 -> 14 -> 15 -> 19 -> 8.
		

Crossrefs

Row n=8 of A259016.

Formula

a(n) = min { m >= 0 : A258851^n(m) = 8 }.

A259409 The pi-based arithmetic derivative of the double factorial of n.

Original entry on oeis.org

0, 0, 1, 2, 12, 19, 128, 193, 1600, 2997, 20224, 37692, 319488, 552366, 5164032, 10853055, 103268352, 198691110, 2199453696, 4050806490, 49934499840, 102089892240, 1176592711680, 2471811316695, 32489204613120, 71282307214125, 893769083781120, 2351538388135125
Offset: 0

Views

Author

Alois P. Heinz, Jun 26 2015

Keywords

Crossrefs

Programs

  • Maple
    with(numtheory):
    d:= n-> n*add(i[2]*pi(i[1])/i[1], i=ifactors(n)[2]):
    a:= proc(n) option remember;
          `if`(n<2, 0, a(n-2)*n+doublefactorial(n-2)*d(n))
        end:
    seq(a(n), n=0..40);
  • Mathematica
    d[n_] := n*Sum[i[[2]]*PrimePi[i[[1]]]/i[[1]], {i, FactorInteger[n]}];
    a[n_] := a[n] = If[n < 2, 0, a[n-2]*n + (n-2)!!*d[n]];
    Table[a[n], {n, 0, 40}] (* Jean-François Alcover, May 02 2022, after Alois P. Heinz *)

Formula

a(n) = A258851(n!!) = A258851(A006882(n)).

A258847 Sum of the k-th pi-based arithmetic derivative of n-k for k=0..n.

Original entry on oeis.org

0, 1, 2, 4, 6, 10, 13, 20, 21, 33, 54, 86, 146, 339, 788, 2947, 14870, 94801, 706961, 5566784, 43958933, 317950465, 2406052444, 19645433193, 146175038733, 1479263447899, 16135114175706, 203382520812382, 2606355260220040, 32974597626726301, 406609097787758227
Offset: 0

Views

Author

Alois P. Heinz, Jun 12 2015

Keywords

Crossrefs

Antidiagonal sums of A258850.

Programs

  • Maple
    with(numtheory):
    d:= n-> n*add(i[2]*pi(i[1])/i[1], i=ifactors(n)[2]):
    A:= proc(n, k) option remember; `if`(k=0, n, d(A(n, k-1))) end:
    a:= proc(n) option remember; add(A(h, n-h), h=0..n) end:
    seq(a(n), n=0..30);

Formula

a(n) = Sum_{k=0..n} A258850(n-k,k).

A258849 The n-th pi-based arithmetic derivative of n.

Original entry on oeis.org

0, 0, 0, 0, 4, 0, 4, 4, 12288, 81920, 0, 0, 278380544, 4, 4931584, 278380544, 14768867966976, 4, 128412352512, 14768867966976, 375877192068366336, 14768867966976, 14768867966976, 375877192068366336
Offset: 0

Views

Author

Alois P. Heinz, Jun 12 2015

Keywords

Crossrefs

Main diagonal of A258850.

Programs

  • Maple
    with(numtheory):
    d:= n-> n*add(i[2]*pi(i[1])/i[1], i=ifactors(n)[2]):
    A:= proc(n, k) option remember; `if`(k=0, n, d(A(n, k-1))) end:
    a:= n-> A(n$2):
    seq(a(n), n=0..23);

Formula

a(n) = A258851^n(n) = A258850(n,n).

A259168 a(n) = n-th pi-based antiderivative of 7.

Original entry on oeis.org

7, 6, 13, 41, 35, 38, 163, 138, 253, 346, 1383, 630, 4657, 3210, 5633, 9469, 20838, 22525, 28491, 21035, 16491, 13735, 22114, 54298, 225361, 639070, 479794, 421883, 720634, 461055, 788446, 650762, 688229, 478126, 1465550, 1960533, 2117157
Offset: 0

Views

Author

Alois P. Heinz, Jun 19 2015

Keywords

Crossrefs

Row n=7 of A259016.

Formula

a(n) = min { m >= 0 : A258851^n(m) = 7 }.

A259170 a(n) = n-th pi-based antiderivative of 9.

Original entry on oeis.org

9, 23, 83, 431, 3001, 27457, 10626, 112087, 87306, 172810, 280217, 390133, 353555, 750243, 1318106, 937023, 367542, 2615090, 3434663, 3281065, 3270774, 4979697, 8021665, 4627825, 5618666, 11169397
Offset: 0

Views

Author

Alois P. Heinz, Jun 19 2015

Keywords

Crossrefs

Row n=9 of A259016.

Formula

a(n) = min { m >= 0 : A258851^n(m) = 9 }.

A259416 The pi-based arithmetic derivative of the n-th Fibonacci number.

Original entry on oeis.org

0, 0, 0, 1, 2, 3, 12, 6, 26, 31, 58, 24, 480, 51, 304, 851, 1537, 251, 6028, 2466, 13789, 12657, 8870, 3121, 222384, 100805, 49405, 290641, 536006, 42613, 2666244, 446497, 3716882, 3111635, 1694821, 10652139, 76062672, 16224451, 27896232, 51359105, 282500593
Offset: 0

Views

Author

Alois P. Heinz, Jun 26 2015

Keywords

Crossrefs

Formula

a(n) = A258851(A000045(n)).

A353509 a(n) = A353379(n) - A001222(n).

Original entry on oeis.org

0, 0, 0, 0, 0, 2, 0, 0, 0, 2, 0, 4, 0, 2, 2, 0, 0, 4, 0, 4, 2, 2, 0, 7, 0, 2, 0, 4, 0, 9, 0, 0, 2, 2, 2, 8, 0, 2, 2, 7, 0, 9, 0, 4, 4, 2, 0, 10, 0, 4, 2, 4, 0, 7, 2, 7, 2, 2, 0, 16, 0, 2, 4, 0, 2, 9, 0, 4, 2, 9, 0, 14, 0, 2, 4, 4, 2, 9, 0, 10, 0, 2, 0, 16, 2, 2, 2, 7, 0, 16, 2, 4, 2, 2, 2, 15, 0, 4, 4, 8, 0, 9
Offset: 1

Views

Author

Antti Karttunen, Apr 29 2022

Keywords

Comments

The difference of A258851 (primepi-based arithmetic derivative) and A056239 (sum of prime indices with multiplicity) applied to A181819, the prime shadow of n.

Crossrefs

Programs

Formula

a(n) = A278510(A181819(n)) = A353379(n) - A001222(n).
Previous Showing 41-49 of 49 results.