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A176358 Partial sums of A002503. 0
5, 19, 46, 87, 131, 196, 272, 362, 471, 596, 735, 887, 1042, 1211, 1397, 1586, 1789, 1997, 2206, 2425, 2652, 2882, 3119, 3384, 3659, 3957, 4264, 4575, 4889, 5210, 5534, 5863, 6207, 6584, 6997, 7416, 7844, 8278, 8717, 9158, 9607, 10065, 10524, 10991 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Partial sums of numbers n such that binomial(2n,n) is divisible by (n+1)^2. The subsequence of primes in this partial sum begins: 5, 19, 131, 887, 1789, 1997, 3119, 3659, 4889, 6997. The subsequence of primes in this partial sum begins: 196.

LINKS

Table of n, a(n) for n=1..44.

FORMULA

a(n) = SUM[i=1..n] A002503(i).

EXAMPLE

a(23) = 5 + 14 + 27 + 41 + 44 + 65 + 76 + 90 + 109 + 125 + 139 + 152 + 155 + 169 + 186 + 189 + 203 + 208 + 209 + 219 + 227 + 230 + 237 = 3119 is prime.

MATHEMATICA

Accumulate[Select[Range[800], Divisible[Binomial[2#, #], (#+1)^2]&]]  (* Harvey P. Dale, Apr 18 2011 *)

CROSSREFS

Cf. A002503, A065350, A000108, A065344-A065349.

Sequence in context: A146395 A154302 A146736 * A045458 A120289 A293457

Adjacent sequences:  A176355 A176356 A176357 * A176359 A176360 A176361

KEYWORD

easy,nonn

AUTHOR

Jonathan Vos Post, Apr 15 2010

EXTENSIONS

Corrected by Harvey P. Dale, Apr 18 2011.

STATUS

approved

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Last modified September 23 19:41 EDT 2020. Contains 337315 sequences. (Running on oeis4.)