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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A160668 Distance between prime(n) and the next higher power of 10.

Original entry on oeis.org

8, 7, 5, 3, 89, 87, 83, 81, 77, 71, 69, 63, 59, 57, 53, 47, 41, 39, 33, 29, 27, 21, 17, 11, 3, 899, 897, 893, 891, 887, 873, 869, 863, 861, 851, 849, 843, 837, 833, 827, 821, 819, 809, 807, 803, 801, 789, 777, 773, 771, 767, 761, 759, 749, 743, 737, 731, 729, 723
Offset: 1

Views

Author

Enoch Haga, May 23 2009

Keywords

Examples

			a(1)=8 because 10^1=10, and 10-2, 1st prime 2, = 8;
a(5)=89 because 10^2=100 and 100-11, 5th prime 11, = 89.

Links

Crossrefs

Cf. A000040, A055642, A061601, A160669, A160670, A228628.

Programs

  • Magma
    [10^(Ceiling(Log(NthPrime(n))/Log(10))) - NthPrime(n): n in [1..30]]; // G. C. Greubel, May 02 2018
  • Maple
    a:= n-> (p-> 10^length(p)-p)(ithprime(n)):
seq(a(n), n=1..100);  # Alois P. Heinz, Dec 08 2017
  • Mathematica
    Table[10^Ceiling[Log[Prime[n]]/Log[10]] - Prime[n], {n, 1, 100}] (* G. C. Greubel, May 02 2018 *)
  • PARI
    a(n) = 10^ceil(log(prime(n))/log(10)) - prime(n); \\ Michel Marcus, Dec 08 2017
  • UBASIC
    20 N=3:print N:C=2
30 A=3:S=sqrt(N)
40 B=N/A 50 if A*B=int(N) then 70
60 A=A+2:if AEnoch Haga, May 22 2009

Formula

From Alois P. Heinz, Dec 08 2017: (Start)
a(n) = 10^A055642(A000040(n)) - A000040(n).
a(n) = A228628(n) + 1 = A061601(A000040(n)) + 1. (End)

A160670 Duplicate of A145985.

Original entry on oeis.org

7, 5, 3, 89, 83, 71, 59, 53, 47, 41, 29, 17, 11, 3, 887, 863, 827, 821, 809, 773, 761, 743, 719, 683, 653, 647, 641, 617, 599, 569, 557, 521, 509, 491, 479, 443, 431, 401, 383, 359, 353, 347, 317, 281, 257, 239, 227, 191, 179, 173, 137, 113, 89, 71, 59, 53, 47, 29
Offset: 1

Views

Author

Enoch Haga, May 23 2009

Keywords

Comments

Previous name was: Primes in A160668 in order of appearance.

Crossrefs

Cf. A160668, A160669.

Programs

  • UBASIC
    10 'recipseq, Enoch Haga, May 22 2009
20 N=3:print N:C=2
30 A=3:S=sqrt(N)
40 B=N/A
50 if A*B=int(N) then 70
60 A=A+2:if A
Showing 1-2 of 2 results.

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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