A194553 Centered cube numbers: (n+1)^25 + n^25.

1, 33554433, 847322163875, 1126747195452067, 299149123783795749, 28728311253806654501, 1369498907693894602183, 39120000482621126610375, 755676919554809750479817, 10717897987691852588770249, 118347059433883722041830251

Offset

0,2

Comments

Can never be prime as a(n) = (2*n+1) * (n^4 + 2*n^3 + 4*n^2 + 3*n+1) * (n^20 + 10*n^19 + 120*n^18 + 795*n^17 + 3685*n^16 + 12752*n^15 + 33965*n^14 + 71205*n^13 + 119580*n^12 + 162965*n^11 + 181754*n^10 + 166595*n^9 + 125515*n^8 +77415*n^7 + 38745*n^6 + 15503*n^5 + 4845*n^4 + 1140*n^3 + 190*n^2 + 20*n + 1).

Links

Vincenzo Librandi, Table of n, a(n) for n = 0..10000

Index entries for linear recurrences with constant coefficients, signature (26, -325, 2600, -14950, 65780, -230230, 657800, -1562275, 3124550, -5311735, 7726160, -9657700, 10400600, -9657700, 7726160, -5311735, 3124550, -1562275, 657800, -230230, 65780, -14950, 2600, -325, 26, -1).

Mathematica

Total/@Partition[Range[0, 20]^25, 2, 1] (* Harvey P. Dale, Dec 03 2015 *)

Prog

(Magma) [(n+1)^25+n^25: n in [0..10]]; // Vincenzo Librandi, Sep 21 2011

Crossrefs

Cf. A000040, A036085-A036102, A100267, A154535, A100266, A152913, A194155, A194185, A194216.

Sequence in context: A010813 A323661 A281959 * A246108 A184984 A143511

Adjacent sequences: A194550 A194551 A194552 * A194554 A194555 A194556

Keyword

nonn,easy

Author

Jonathan Vos Post, Aug 28 2011

Status

approved