A261071 a(n) = 2^(n!) + 1.

3, 5, 65, 16777217, 1329227995784915872903807060280344577

Offset

1,1

Comments

a(n) is a sum of two k-th powers of positive integers for k=1,2,...,n.

Links

Table of n, a(n) for n=1..5.

Formula

a(n) = 2^(n!) + 1.

a(n) = A050923(n) + 1.

Example

a(3) = 2^6 + 1 = 65.

Mathematica

Array[2^#! + 1 &, 6] (* Paolo Xausa, Jan 31 2024 *)

Prog

(PARI) first(m)=vector(m, i, 2^(i!)+1); /* Anders Hellström, Aug 08 2015 */
(Magma) [2^(Factorial(n)) + 1: n in [1..6]]; // Vincenzo Librandi, Aug 09 2015

Crossrefs

Cf. A050923.

Sequence in context: A318546 A076513 A222611 * A247862 A348205 A145616

Adjacent sequences: A261068 A261069 A261070 * A261072 A261073 A261074

Keyword

nonn,easy

Author

Marco Ripà, Aug 08 2015

Status

approved