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.

A342006 Numbers k where the maximal prime exponent in the arithmetic derivative of A276086(k) attains the maximal exponent in A276086(k), where A276086 gives the prime product form of primorial base expansion of its argument.

Original entry on oeis.org

3, 7, 8, 9, 13, 16, 31, 32, 33, 36, 37, 38, 39, 44, 45, 64, 70, 72, 80, 92, 100, 144, 156, 211, 212, 213, 214, 216, 217, 218, 219, 222, 224, 232, 240, 241, 242, 243, 244, 246, 247, 248, 249, 252, 253, 271, 272, 280, 287, 288, 296, 300, 303, 308, 316, 348, 388, 424, 432, 440, 448, 450, 452, 460, 462, 480, 488, 493, 496
Offset: 1

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Author

Antti Karttunen, Mar 03 2021

Keywords

Comments

Numbers k for which A328391(k) >= A328114(k).

Examples

			16 is present as A276086(16) = 225, A003415(225) = 240 = 2^4 * 3 * 5, with maximum exponent = 4 >= the maximal exponent 4 in 16 = 2^4.
		

Crossrefs

Positions of zeros in A342005.

Programs

  • PARI
    A328114(n) = { my(s=0, p=2); while(n, s = max(s,(n%p)); n = n\p; p = nextprime(1+p)); (s); };
    A051903(n) = if((1==n),0,vecmax(factor(n)[, 2]));
    A327860(n) = { my(s=0, m=1, p=2, e); while(n, e = (n%p); m *= (p^e); s += (e/p); n = n\p; p = nextprime(1+p)); (s*m); };
    A328391(n) = A051903(A327860(n));
    isA342006(n) = (A328391(n) >= A328114(n));
    
  • PARI
    isA342006(n) = (0==A342005(n));