OFFSET
1
COMMENTS
Characteristic function for the range of A037019.
LINKS
PROG
(PARI) A323509(n) = { my(f = factor(n)); for(i=1, #f~, if((primepi(f[i, 1])!=i)||!isprime(1+f[i, 2])||((i>1)&&(f[i-1, 2]<f[i, 2])), return(0))); (1); };
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, Jan 18 2019
STATUS
approved