A353267 The least number with the same prime factorization pattern (A348717) as A332449(n) = A005940(1+(3*A156552(n))).

1, 4, 4, 10, 4, 16, 4, 30, 10, 36, 4, 22, 4, 100, 16, 90, 4, 40, 4, 250, 36, 196, 4, 66, 10, 484, 30, 490, 4, 64, 4, 270, 100, 676, 16, 154, 4, 1156, 196, 750, 4, 144, 4, 1210, 22, 1444, 4, 198, 10, 84, 484, 1690, 4, 120, 36, 1470, 676, 2116, 4, 34, 4, 3364, 250, 810, 100, 400, 4, 2890, 1156, 324, 4, 462, 4, 3844

Offset: 1

Author

Antti Karttunen, Apr 09 2022

Keywords

• nonn

Links

• Index entries for sequences computed from indices in prime factorization

Crossrefs

Cf. A005940, A156552, A332449, A348717.

Cf. also A305897 (rgs-transform), A352892, A353268.

Programs

PARI

A005940(n) = { my(p=2, t=1); n--; until(!n\=2, if((n%2), (t*=p), p=nextprime(p+1))); (t); };
A156552(n) = { my(f = factor(n), p, p2 = 1, res = 0); for(i = 1, #f~, p = 1 << (primepi(f[i, 1]) - 1); res += (p * p2 * (2^(f[i, 2]) - 1)); p2 <<= f[i, 2]); res };
A332449(n) = A005940(1+(3*A156552(n)));
A348717(n) = { my(f=factor(n)); if(#f~>0, my(pi1=primepi(f[1, 1])); for(k=1, #f~, f[k, 1] = prime(primepi(f[k, 1])-pi1+1))); factorback(f); }; \\ From A348717
A353267(n) = A348717(A332449(n));

Formula

a(n) = A348717(A332449(n)) = A332449(A348717(n)).