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.

A351256 Maximal exponent in the prime factorization of A351255(n).

Original entry on oeis.org

0, 1, 1, 1, 2, 2, 1, 1, 1, 2, 2, 3, 3, 4, 1, 1, 1, 1, 2, 1, 1, 2, 2, 2, 2, 3, 3, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 4, 4, 4, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 5, 5, 6, 6, 6, 6, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 3, 3, 3, 4, 4, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 4, 2, 2, 2, 2, 3, 3, 4, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 5, 5, 6, 6, 6, 6
Offset: 1

Views

Author

Antti Karttunen, Feb 11 2022

Keywords

Comments

The largest digit in the primorial base representation of A328116(n).
The scatter plot gives some sense of how it is harder to eventually reach zero by iterating A003415, when starting from a number with large exponent(s) in its prime factorization. See also A099308.

Examples

			A328116(27) = 50, and A049345(50) = "1310", where the largest primorial base digit is 3, therefore a(27) = 3. Equally, A351255(27) = 2625 = 3 * 5^3 * 7, thus A051903(2625) = 3 and a(27) = 3.
		

Crossrefs

Programs

  • PARI
    A003415checked(n) = if(n<=1, 0, my(f=factor(n), s=0); for(i=1, #f~, if(f[i,2]>=f[i,1],return(0), s += f[i, 2]/f[i, 1])); (n*s));
    A051903(n) = if((1==n),0,vecmax(factor(n)[, 2]));
    A276086(n) = { my(m=1, p=2); while(n, m *= (p^(n%p)); n = n\p; p = nextprime(1+p)); (m); };
    A099307(n) = { my(s=1); while(n>1, n = A003415checked(n); s++); if(n,s,0); };
    for(n=0, 2^9, u=A276086(n); c = A099307(u); if(c>0,print1(A051903(u), ", ")));

Formula

a(n) = A328114(A328116(n)) = A051903(A351255(n)).
For all n, a(n) < A351257(n). [See A351258 for the differences].