A166701 - OEIS

%I #8 Nov 15 2025 23:00:02

%S 1,5,9,25,29,45,49,125,81,145,149,225,229,245,261,625,629,405,409,725,

%T 441,745,749,1125,841,1145,729,1225,1229,1305,1309,3125,1341,3145,

%U 1421,2025,2029,2045,2061,3625,3629,2205,2209,3725,2349,3745,3749,5625,2401

%N Totally multiplicative sequence with a(p) = a(p-1) + 4 for prime p.

%H Andrew Howroyd, <a href="/A166701/b166701.txt">Table of n, a(n) for n = 1..10000</a>

%F Multiplicative with a(p^e) = (a(p-1)+4)^e. If n = Product p(k)^e(k) then a(n) = Product (a(p(k)-1)+4)^e(k).

%o (PARI) lista(n)={my(a=vector(n)); for(n=1, n, my(f=factor(n)); a[n] = prod(i=1, #f~, my([p,e]=f[i,]); (a[p-1] + 4)^e)); a} \\ _Andrew Howroyd_, Nov 15 2025

%Y Cf. A166699.

%K nonn,mult

%O 1,2

%A _Jaroslav Krizek_, Oct 18 2009