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

Author

Omar E. Pol, Feb 21 2014

Keywords

• nonn
• easy

Comments

Partial sums of A006005.

Examples

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

Crossrefs

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

Programs

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 *)

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

Formula

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