OFFSET
1,8
COMMENTS
A prime index of n is a number m such that prime(m) divides n. The multiset of prime indices of n is row n of A112798.
LINKS
FORMULA
EXAMPLE
The prime indices of 6500 are {1,1,3,3,3,6}, with nonfixed points at positions {2,4,5}, so a(6500) = 3.
MATHEMATICA
pnq[y_]:=Length[Select[Range[Length[y]], #!=y[[#]]&]];
Table[pnq[If[n==1, {}, Flatten[Cases[FactorInteger[n], {p_, k_}:>Table[PrimePi[p], {k}]]]]], {n, 100}]
PROG
(PARI) A352823(n) = { my(f=factor(n), i=0, c=0); for(k=1, #f~, while(f[k, 2], f[k, 2]--; i++; c += (i!=primepi(f[k, 1])))); (c); }; \\ Antti Karttunen, Apr 11 2022
CROSSREFS
* = unproved
Positions of zeros are A002110
Positions of first appearances are A077552.
The complement triangle version is A238352.
The complement is A352822.
A122111 represents partition conjugation using Heinz numbers.
KEYWORD
nonn
AUTHOR
Gus Wiseman, Apr 05 2022
EXTENSIONS
Data section extended up to 105 terms by Antti Karttunen, Apr 11 2022
STATUS
approved