A237589 Sum of first n odd noncomposite numbers.

1, 4, 9, 16, 27, 40, 57, 76, 99, 128, 159, 196, 237, 280, 327, 380, 439, 500, 567, 638, 711, 790, 873, 962, 1059, 1160, 1263, 1370, 1479, 1592, 1719, 1850, 1987, 2126, 2275, 2426, 2583, 2746, 2913, 3086, 3265, 3446, 3637, 3830, 4027, 4226, 4437, 4660, 4887

Offset

1,2

Comments

Partial sums of A006005.

Links

Table of n, a(n) for n=1..49.

Formula

a(n) = A007504(n) - 1 = A014284(n+1) - 2.

Example

For n = 5 the first five odd noncomposite numbers are 1, 3, 5, 7, 11, so a(5) = 1 + 3 + 5 + 7 + 11 = 27.

Maple

a := proc(n) option remember; `if`(n=1, 1, a(n-1) + ithprime(n)) end:
seq(a(n), n=1..49); # Peter Luschny, Sep 20 2018

Mathematica

a[1]=1; a[n_]:=a[n]=a[n-1]+Prime[n]; Table[a[n], {n, 1, 49}] (* Robert P. P. McKone, Jan 18 2022 *)

Prog

(PARI) terms(n) = my(s=1, i=0); forprime(p=3, , if(i >= n, break, print1(s, ", "); i++; s=s+p))
/* Print initial 50 terms as follows */
terms(50) \\ Felix Fröhlich, Sep 20 2018

Crossrefs

Cf. A000040, A006005, A007504, A008578, A014284.

Sequence in context: A066969 A213495 A109593 * A138981 A138993 A339330

Adjacent sequences: A237586 A237587 A237588 * A237590 A237591 A237592

Keyword

nonn,easy

Author

Omar E. Pol, Feb 21 2014

Status

approved