A342457 - OEIS

%I #11 Mar 18 2021 22:57:00

%S 2,2,2,4,2,4,6,6,2,4,64,16,324,36,10,36,2,4,64,16,2304,96,486,24,7290,

%T 104976,21600,1296,1708593750000,100,93750,10,2,4,64,16,144,6,216,6,

%U 172186884,7776,2160,216,216000000,236196,10497600,54,10935000000000,53144100,1476225000000,7290,122500000000,10935000,140,360

%N Terms of A342456 prime-shifted so far towards lower primes that they become even: a(n) = 2*A246277(A342456(n)).

%C These terms have the same prime signature as the corresponding terms in A342456, thus applying omega and bigomega to these gives the same derived sequences A342461 and A342462.

%H <a href="/index/Bi#binary">Index entries for sequences related to binary expansion of n</a>

%H <a href="/index/Pri#primorialbase">Index entries for sequences related to primorial base</a>

%F a(n) = 2*A246277(A342456(n)) = 2*A329038(A329886(n)).

%o (PARI)

%o A246277(n) = if(1==n, 0, my(f = factor(n), k = primepi(f[1,1])-1); for (i=1, #f~, f[i,1] = prime(primepi(f[i,1])-k)); factorback(f)/2);

%o A342457(n) = 2*A246277(A342456(n)); \\ Uses also code from A342456.

%Y Cf. A246277, A276086, A283980, A329038, A329886, A342456, A342461 [= A001221(a(n))], A342462 [= A001222(a(n))], A342464 [= A051903(a(n))].

%K nonn

%O 0,1

%A _Antti Karttunen_, Mar 15 2021