OFFSET
1,1
COMMENTS
Sequence A277316 sorted into ascending order. See comments in that entry.
Terms k present in A277319 for which A260443(A048675(k)) = k. - David A. Corneth and Antti Karttunen, Oct 13 2016
PROG
(PARI)
\\ Naive program that does not work very far:
A003961(n) = my(f = factor(n)); for (i=1, #f~, f[i, 1] = nextprime(f[i, 1]+1)); factorback(f); \\ From Michel Marcus
A048675(n) = my(f = factor(n)); sum(k=1, #f~, f[k, 2]*2^primepi(f[k, 1]))/2; \\ Michel Marcus, Oct 10 2016
isA277317 = n -> isprime(A277333(n)); \\ Naive version, very slow.
A061395(n) = if(1==n, 0, primepi(vecmax(factor(n)[, 1]))); \\ After M. F. Hasler's code for A006530.
isA277317(n) = { my(k); if(3==n, 1, if(n%2 || (omega(n) < A061395(n)), 0, k = A048675(n); if((A260443(k) == n), isprime(k), 0))); }; \\ Somewhat optimized.
i=0; n=0; while(i < 30, n++; if(isA277317(n), i++; write("b277317.txt", i, " ", n)));
(Scheme, with Antti Karttunen's IntSeq-library)
;; Doing search in another order:
CROSSREFS
Cf. A277316.
KEYWORD
nonn,more
AUTHOR
Antti Karttunen, Oct 10 2016
STATUS
approved