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.

A090455 Difference between numbers of binary 1's of n and binary 1's of n-th prime.

Original entry on oeis.org

0, -1, 0, -2, -1, -1, 1, -2, -2, -2, -2, -1, 0, -1, -1, -3, -3, -3, 0, -2, 0, -2, 0, -2, 0, -1, -1, -2, -1, 0, -2, -2, -1, -2, -1, -3, -2, -1, -1, -3, -2, -2, -3, 0, 0, -1, 0, -5, -2, -2, -1, -4, -1, -3, 3, -1, 0, -1, 1, 0, 0, 1, 1, -5, -3, -4, -2, -2, -3, -3, 0, -4, -4, -3
Offset: 1

Views

Author

Reinhard Zumkeller, Dec 01 2003

Keywords

Crossrefs

Programs

  • Mathematica
    Table[DigitCount[n,2,1]-DigitCount[Prime[n],2,1],{n,80}] (* Harvey P. Dale, Aug 08 2013 *)

Formula

a(n) = A000120(n) - A014499(n);
a(A071600(n)) = a(A049084(A072439(n))) = 0.
a(A049084(A090456(n))) < 0.
a(A049084(A090457(n))) > 0.

Extensions

Definition clarified by Harvey P. Dale, Aug 08 2013

A090433 Primes p(k) having a smaller sum of digits than k.

Original entry on oeis.org

11, 13, 23, 61, 101, 103, 107, 109, 151, 163, 211, 223, 227, 241, 251, 271, 311, 313, 317, 331, 337, 347, 401, 421, 431, 433, 443, 461, 503, 509, 521, 523, 701, 911, 1009, 1013, 1021, 1031, 1033, 1051, 1061, 1063, 1103, 1109, 1117, 1123, 1129, 1151
Offset: 1

Views

Author

Reinhard Zumkeller, Dec 01 2003

Keywords

Comments

A090431(a(n)) > 0.

Crossrefs

Programs

  • Mathematica
    Select[Prime[Range[200]],Total[IntegerDigits[#]]Harvey P. Dale, Mar 05 2017 *)

A090456 Primes prime(k) having more binary 1's than k.

Original entry on oeis.org

3, 7, 11, 13, 19, 23, 29, 31, 37, 43, 47, 53, 59, 61, 71, 79, 89, 101, 103, 107, 109, 127, 131, 137, 139, 149, 151, 157, 163, 167, 173, 179, 181, 191, 199, 223, 227, 229, 233, 239, 241, 251, 263, 271, 311, 313, 317, 331, 337, 347, 349, 359, 367, 373, 379, 383
Offset: 1

Views

Author

Reinhard Zumkeller, Dec 01 2003

Keywords

Crossrefs

Programs

  • Mathematica
    Select[Prime[Range[100]], Differences[DigitCount[{PrimePi[#], #}, 2, 1]][[1]] > 0 &] (* Amiram Eldar, Apr 23 2022 *)

Formula

A090455(a(n)) < 0.
Showing 1-3 of 3 results.