A104344
a(n) = Sum_{k=1..n} k!^2.
Original entry on oeis.org
1, 5, 41, 617, 15017, 533417, 25935017, 1651637417, 133333531817, 13301522971817, 1606652445211817, 231049185247771817, 39006837228880411817, 7639061293780877851817, 1717651314017980301851817, 439480788011413032845851817, 126953027293558583218061851817
Offset: 1
-
Table[Sum[(k!)^2,{k,n}],{n,15}] (* Harvey P. Dale, Jul 21 2011 *)
Accumulate[(Range[20]!)^2] (* Much more efficient than the above program. *) (* Harvey P. Dale, Aug 15 2022 *)
-
a(n) = sum(k=1, n, k!^2); \\ Michel Marcus, Jul 16 2017
A100289
Numbers k such that (1!)^2 + (2!)^2 + (3!)^2 + ... + (k!)^2 is prime.
Original entry on oeis.org
2, 3, 4, 5, 7, 8, 10, 18, 21, 42, 51, 91, 133, 177, 182, 310, 3175, 9566, 32841
Offset: 1
Cf.
A100288 (primes of the form (1!)^2 + (2!)^2 + (3!)^2 +...+ (k!)^2).
Cf.
A061062 ((0!)^2 + (1!)^2 + (2!)^2 + (3!)^2 +...+ (n!)^2).
-
L:= [seq((i!)^2, i=1..1000)]:
S:= ListTools:-PartialSums(L):
select(t -> isprime(S[t]), [$1..1000]); # Robert Israel, Jul 17 2017
-
Select[Range[200], PrimeQ[Total[Range[#]!^2]] &]
Module[{nn=350,tt},tt=Accumulate[(Range[nn]!)^2];Position[tt,?PrimeQ]]//Flatten (* The program generates the first 16 terms of the sequence. *) (* _Harvey P. Dale, Oct 12 2023 *)
-
is(n)=ispseudoprime(sum(k=1,n,k!^2)) \\ Charles R Greathouse IV, Apr 14 2015
A100288
Primes of the form (1!)^2 + (2!)^2 + (3!)^2 +...+ (k!)^2.
Original entry on oeis.org
5, 41, 617, 15017, 25935017, 1651637417, 13301522971817, 41117342095090841723228045851817, 2616218222822143606864564493635469851817
Offset: 1
41 = (1!)^2 + (2!)^2 + (3!)^2 is prime.
Cf.
A100289 (k such that (1!)^2 + (2!)^2 + (3!)^2 + ... + (k!)^2 is prime).
-
Select[Accumulate[Table[(n!)^2,{n,30}]],PrimeQ] (* Harvey P. Dale, May 09 2025 *)
-
lista(nn) = {my(s=1); for(k=2, nn, s+=(k!)^2; if(ispseudoprime(s), print1(s, ", "))); } \\ Jinyuan Wang, Mar 08 2020
A101746
Primes of the form ((0!)^2+(1!)^2+(2!)^2+...+(n!)^2)/6.
Original entry on oeis.org
7, 103, 2503, 88903, 4322503, 2473107965928318342544472044975303
Offset: 1
-
f2=1; s=2; Do[f2=f2*n*n; s=s+f2; If[PrimeQ[s/6], Print[{n, s/6}]], {n, 2, 100}]
Select[Accumulate[(Range[0,25]!)^2]/6,PrimeQ] (* Harvey P. Dale, Aug 31 2021 *)
A289948
a(n) = Sum_{k=0..n} k!^3.
Original entry on oeis.org
1, 2, 10, 226, 14050, 1742050, 374990050, 128399054050, 65676719822050, 47850402559694050, 47832576242431694050, 63649302669112063694050, 109966989623147836159694050, 241567605673714904675071694050, 662801328154821495670649599694050, 2236801993181528581580834681599694050
Offset: 0
-
With[{nn = 16}, Table[Total@ Take[#, n], {n, nn}] &@ Table[k!^3, {k, 0, nn}]] (* Michael De Vlieger, Jul 16 2017 *)
Accumulate[(Range[0,20]!)^3] (* Harvey P. Dale, Nov 30 2017 *)
-
a(n) = sum(k=0, n, k!^3); \\ Michel Marcus, Jul 16 2017
A289949
a(n) = Sum_{k=0..n} k!^4.
Original entry on oeis.org
1, 2, 18, 1314, 333090, 207693090, 268946253090, 645510228813090, 2643553803594573090, 17342764866576345933090, 173418555892594089945933090, 2538940579958951120707545933090, 52646414799433780559063261145933090, 1503614384819523432725006336630745933090
Offset: 0
A101747
Numbers n such that ((0!)^2+(1!)^2+(2!)^2+...+(n!)^2)/6 is prime.
Original entry on oeis.org
3, 4, 5, 6, 7, 19, 40, 56, 93
Offset: 1
-
f2=1; s=2; Do[f2=f2*n*n; s=s+f2; If[PrimeQ[s/6], Print[{n, s/6}]], {n, 2, 100}]
A173476
Triangle T(n, k) = 1 + (k!)^2 - 2*k!*(n-k)! + ((n-k)!)^2, read by rows.
Original entry on oeis.org
1, 1, 1, 2, 1, 2, 26, 2, 2, 26, 530, 26, 1, 26, 530, 14162, 530, 17, 17, 530, 14162, 516962, 14162, 485, 1, 485, 14162, 516962, 25391522, 516962, 13925, 325, 325, 13925, 516962, 25391522, 1625621762, 25391522, 515525, 12997, 1, 12997, 515525, 25391522, 1625621762
Offset: 0
Triangle begins as:
1;
1, 1;
2, 1, 2;
26, 2, 2, 26;
530, 26, 1, 26, 530;
14162, 530, 17, 17, 530, 14162;
516962, 14162, 485, 1, 485, 14162, 516962;
25391522, 516962, 13925, 325, 325, 13925, 516962, 25391522;
1625621762, 25391522, 515525, 12997, 1, 12997, 515525, 25391522, 1625621762;
-
[(Factorial(n-k) -Factorial(k))^2 +1: k in [0..n], n in [0..12]]; // G. C. Greubel, Feb 19 2021
-
Table[((n-k)! -k!)^2 +1, {n,0,12}, {k,0,n}]//Flatten (* modified by G. C. Greubel, Feb 19 2021 *)
-
flatten([[(factorial(n-k) -factorial(k))^2 +1 for k in (0..n)] for n in (0..12)]) # G. C. Greubel, Feb 19 2021
Showing 1-8 of 8 results.
Comments