A139567
Bisection of ultraperfect numbers A139306.
Original entry on oeis.org
8, 512, 33554432, 137438953472, 2658455991569831745807614120560689152
Offset: 1
A139568
Bisection of ultraperfect numbers A139306.
Original entry on oeis.org
32, 8192, 8589934592, 2305843009213693952, 191561942608236107294793378393788647952342390272950272
Offset: 1
A139294
a(n) = 2^(2p - 1), where p is the n-th Mersenne prime A000668(n).
Original entry on oeis.org
32, 8192, 2305843009213693952, 14474011154664524427946373126085988481658748083205070504932198000989141204992
Offset: 1
Cf.
A000079,
A000668,
A139286,
A139295,
A139296,
A139297,
A139298,
A139299,
A139300,
A139301,
A139302,
A139303,
A139304,
A139305,
A139306.
-
A000668 := Select[2^Range[500] - 1, PrimeQ]; Table[2^(2*A000668[[n]] - 1), {n, 1, 5}] (* G. C. Greubel, Oct 03 2017 *)
a[n_] := 2^(2^(MersennePrimeExponent[n] + 1) - 3); Array[a, 4] (* Amiram Eldar, Jul 10 2025 *)
-
\p 100
print1("a(n): "); forprime(q=2, 7, p=2^q-1; if(isprime(p), print1(2^(2*p-1)", ")));
print1("\nNumber of digits in a(n): "); forprime(q=2, 127, p=2^q-1; if(isprime(p), print1(ceil((2*p-1)*log(2)/log(10))", "))) \\ Jens Kruse Andersen, Jul 14 2014
A139286
a(n) = 2^(2*prime(n) - 1).
Original entry on oeis.org
8, 32, 512, 8192, 2097152, 33554432, 8589934592, 137438953472, 35184372088832, 144115188075855872, 2305843009213693952, 9444732965739290427392, 2417851639229258349412352, 38685626227668133590597632, 9903520314283042199192993792
Offset: 1
Cf.
A000040,
A000079,
A076274,
A139287,
A139288,
A139289,
A139290,
A139291,
A139292,
A139293,
A139294,
A139306.
A139295
a(n) = 2^(2p - 1)-1, where p is the n-th Mersenne prime A000668(n).
Original entry on oeis.org
31, 8191, 2305843009213693951, 14474011154664524427946373126085988481658748083205070504932198000989141204991
Offset: 1
Cf.
A000668,
A139294,
A139296,
A139297,
A139298,
A139299,
A139300,
A139301,
A139302,
A139303,
A139304,
A139305,
A139306.
A139296
a(n) = 2^(2p - 1)/2, where p is the n-th Mersenne prime A000668(n).
Original entry on oeis.org
16, 4096, 1152921504606846976, 7237005577332262213973186563042994240829374041602535252466099000494570602496
Offset: 1
Cf.
A000668,
A139286,
A139294,
A139295,
A139297,
A139298,
A139299,
A139300,
A139301,
A139302,
A139303,
A139304,
A139305,
A139306.
A139297
a(n) = 2^(2p - 1)/2-1, where p is the n-th Mersenne prime A000668(n).
Original entry on oeis.org
15, 4095, 1152921504606846975, 7237005577332262213973186563042994240829374041602535252466099000494570602495
Offset: 1
Cf.
A000668,
A139294,
A139295,
A139296,
A139298,
A139299,
A139300,
A139301,
A139302,
A139303,
A139304,
A139305,
A139306.
A139298
a(n) = 2^(2p - 1)/4, where p is the n-th Mersenne prime A000668(n).
Original entry on oeis.org
8, 2048, 576460752303423488, 3618502788666131106986593281521497120414687020801267626233049500247285301248
Offset: 1
Cf.
A000668,
A139294,
A139295,
A139296,
A139297,
A139299,
A139300,
A139301,
A139302,
A139303,
A139304,
A139305,
A139306.
A139299
a(n) = 2^(2p - 1)/4-1, where p is the n-th Mersenne prime A000668(n).
Original entry on oeis.org
7, 2047, 576460752303423487, 3618502788666131106986593281521497120414687020801267626233049500247285301247
Offset: 1
Cf.
A000668,
A139294,
A139295,
A139296,
A139297,
A139298,
A139300,
A139301,
A139302,
A139303,
A139304,
A139305,
A139306.
A139300
a(n) = 2^(2p - 1)/8, where p is the n-th Mersenne prime A000668(n).
Original entry on oeis.org
4, 1024, 288230376151711744, 1809251394333065553493296640760748560207343510400633813116524750123642650624
Offset: 1
Cf.
A000668,
A139294,
A139295,
A139296,
A139297,
A139298,
A139299,
A139301,
A139302,
A139303,
A139304,
A139305,
A139306.
Showing 1-10 of 33 results.
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