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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A073428 First n-digit prime in the concatenation of odd integers forbidding leading zeros.

Original entry on oeis.org

3, 13, 911, 5791, 79111, 105107, 1232527, 23252729, 113151719, 2527293133, 57911131517, 991011031051, 6769717375777, 13579111315171, 135791113151719, 4547495153555759, 31517192123252729, 719212325272931333, 1131517192123252729, 71921232527293133353
Offset: 1

Views

Author

Zak Seidov, Aug 22 2002

Keywords

Comments

Leading zeros are forbidden (cf. A073176).

Programs

  • Mathematica
    ndpQ[n_] := First[n] != 0 && PrimeQ[FromDigits[n]]; With[{od=Flatten[ IntegerDigits/@ Range[1,501,2]]}, Table[ FromDigits/@ Select[Partition[ od,n,1], ndpQ,1],{n,20}]]//Flatten (* Harvey P. Dale, Feb 12 2013 *)

Extensions

Corrected and extended by Harvey P. Dale, Feb 12 2013
Name modified by Sean A. Irvine, Jan 31 2025
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