OFFSET
1,1
COMMENTS
Numbers n such that A064216(n) < n.
Numbers n such that A064989(2n-1) < n.
Note: This sequence has remarkable but possibly merely coincidental overlap with A053726. On Dec 22 2014, Matthijs Coster mistakenly attached a comment intended for that sequence to this one. On Apr 17 2015, Antti Karttunen noted the error. I have moved the comment to the correct sequence, and have removed Karttunen's note. - Allan C. Wechsler, Aug 01 2022
LINKS
Antti Karttunen, Table of n, a(n) for n = 1..10000
Matthijs Coster, Oplossing Zomerprijsvraag, Pythagoras 54/2 (2014) 4-7.
PROG
(PARI)
default(primelimit, 2^30);
A064989(n) = {my(f); f = factor(n); if((n>1 && f[1, 1]==2), f[1, 2] = 0); for (i=1, #f~, f[i, 1] = precprime(f[i, 1]-1)); factorback(f)};
isA246371(n) = (A064216(n) < n);
n = 0; i = 0; while(i < 10000, n++; if(isA246371(n), i++; write("b246371.txt", i, " ", n)));
(Scheme, with Antti Karttunen's IntSeq-library)
KEYWORD
nonn
AUTHOR
Antti Karttunen, Aug 24 2014
STATUS
approved