A073670 a(1) = 1, a(n) = the smallest composite multiple of n not included earlier such that every partial sum is prime.

1, 4, 6, 8, 10, 12, 42, 24, 72, 20, 132, 36, 52, 14, 30, 16, 68, 54, 76, 80, 126, 88, 92, 168, 150, 78, 108, 280, 290, 210, 310, 32, 198, 136, 140, 144, 222, 114, 234, 40, 410, 294, 172, 176, 90, 138, 282, 48, 784, 50, 510, 156, 424, 378, 440, 672, 342, 58, 590, 180, 366, 124, 252, 320

Offset

1,2

Comments

First 23 terms are the same as in A073669; a(24) = 168 = 7*24 while A073669(24) = 24 = A073669(8). - Zak Seidov, Apr 24 2015

Links

Charles R Greathouse IV, Table of n, a(n) for n = 1..10000

Prog

(PARI) earlier(v, n, k)=for(i=1, n-1, if(v[i]==k, return(k))); 0
list(lim)=my(v=vector(lim\1), s, k); s=v[1]=1; for(n=2, #v, k=n; while(isprime(k) || !isprime(s+k) || earlier(v, n, k), k+=n); s+=k; v[n]=k); v \\ Charles R Greathouse IV, Apr 24 2015

Crossrefs

Cf. A073669.

Sequence in context: A181055 A225506 A073669 * A090169 A190330 A186291

Adjacent sequences: A073667 A073668 A073669 * A073671 A073672 A073673

Keyword

nonn

Author

Amarnath Murthy, Aug 11 2002

Extensions

More terms from Sascha Kurz, Feb 01 2003

Data corrected by Zak Seidov, Apr 24 2015

More terms from Charles R Greathouse IV, Apr 24 2015

Status

approved