OFFSET
1,2
COMMENTS
EXAMPLE
Regarding 14300:
- 14300 = 2^2 * 5^2 * 11 * 13 = prime(1)^2 * prime(3)^2 * prime(5) * prime(6),
- the 2-adic valuation is in correspondence with the 5-adic valuation,
- the 11-adic valuation is in correspondence with the 13-adic valuation,
- the p-adic valuation is in correspondence with itself for any prime number p that does not divide 14300,
- so 14300 is a term.
PROG
(PARI) is(n) = { my (f=factor(n), x=f[, 2]~, pi=apply(primepi, f[, 1]~), u, v); for (k=1, #x, if (((u=setsearch(pi, pi[k]-x[k])) && x[u]==x[k]) || ((v=setsearch(pi, pi[k]+x[k])) && x[v]==x[k]), "OK", return (0))); return (1) }
CROSSREFS
KEYWORD
nonn
AUTHOR
Rémy Sigrist, Aug 07 2020
STATUS
approved