This site is supported by donations to The OEIS Foundation.

 Please make a donation to keep the OEIS running. We are now in our 55th year. In the past year we added 12000 new sequences and reached 8000 citations (which often say "discovered thanks to the OEIS"). We need to raise money to hire someone to manage submissions, which would reduce the load on our editors and speed up editing. Other ways to donate

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A173423 Triangular numbers which are sums of 6 consecutive primes. 1
 630, 990, 2926, 4950, 5886, 12720, 24090, 44850, 60726, 81810, 107416, 128778, 152076, 168490, 177906, 202566, 217470, 258840, 277140, 301476, 314028, 408156, 499500, 613278, 695610, 875826, 903840, 940506, 1205128, 1332528, 1405326 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Chai Wah Wu, Table of n, a(n) for n = 1..10000 (n = 1..528 from Robert Israel) MAPLE Primes:= select(isprime, [2, seq(i, i=3..10^7, 2)]): P6:= Primes[1..-6]+Primes[2..-5]+Primes[3..-4]+Primes[4..-3]+Primes[5..-2]+Primes[6..-1]: select(t -> issqr(8*t+1), P6): # Robert Israel, Sep 26 2016 MATHEMATICA f[n_]:=Prime[n]+Prime[n+1]+Prime[n+2]+Prime[n+3]+Prime[n+4]+Prime[n+5]; Select[Table[f[n], {n, 9!}], IntegerQ[Sqrt[1+8# ]]&] PROG (MAGMA) [ t: n in [1..22000] | IsSquare(8*t+1) where t is &+[NthPrime(n+s): s in [0..5]] ]; // Bruno Berselli, Apr 28 2011 CROSSREFS Cf. A000040, A000217, A111163, A167788, A173420, A173421. Sequence in context: A098261 A256937 A177421 * A295769 A110904 A171258 Adjacent sequences:  A173420 A173421 A173422 * A173424 A173425 A173426 KEYWORD nonn AUTHOR Vladimir Joseph Stephan Orlovsky, Feb 18 2010 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified December 15 03:48 EST 2019. Contains 329990 sequences. (Running on oeis4.)