A367629 a(n) = 2^2^(n + 1) - 2^(n + 2).

8, 240, 65504, 4294967232, 18446744073709551488, 340282366920938463463374607431768211200, 115792089237316195423570985008687907853269984665640564039457584007913129639424

Offset

1,1

Comments

a(n) is the absolute value totals of the characteristic polynomial coefficients of n-qubit normalized Hadamard matrices, excluding the 2nd and next-to-last nonzero entries.

a(n) is also the total of the entries in row 2^(n+1) of Pascal's triangle (A007318), excluding the 2nd and next-to-last entries.

Links

J Gregory Moxness, Table of n, a(n) for n = 1..10

Formula

a(n) = A107584(2^n).

Mathematica

Table[2^2^(n+1)-2^(n+2), {n, 10}] (* Harvey P. Dale, Aug 23 2024 *)

Prog

(Python)
def A367629(n): return (1<<(m:=1<<n+1))-(m<<1) # Chai Wah Wu, Nov 29 2023

Crossrefs

Cf. A007318, A107584.

Sequence in context: A302005 A301778 A158263 * A221417 A351367 A351370

Adjacent sequences: A367626 A367627 A367628 * A367630 A367631 A367632

Keyword

nonn,easy

Author

J Gregory Moxness, Nov 24 2023

Extensions

Previous Mathematica program replaced by Harvey P. Dale, Aug 23 2024

Status

approved