A135548 Numbers in A134651 which are the sum of two terms from A001043 in a unique way.

10, 13, 16, 17, 20, 23, 24, 26, 29, 30, 32, 35, 38, 41, 44, 47, 50, 57, 64, 65, 68, 70, 73, 80, 82, 83, 88, 89, 94, 95, 105, 110, 117, 118, 125, 133, 140, 143, 148, 149, 154, 157, 167, 176, 177, 178, 182, 191, 192, 200, 203, 208, 209, 215, 221, 227, 236, 242

Offset

1,1

Comments

Numbers that are the sum of two terms of A001043, but not sum of a different pair of two terms.

Links

Table of n, a(n) for n=1..58.

Example

Recall that A001043 begins with 5,8,12,18,24,30,36,42,52,60,68,78,84,90, ...
So 48 is not in the sequence because 48 = 18+30 = 24+24.
But 88 is in the sequence as it is only = 52+36.
And 89 is there too because = 84+5.

Prog

(PARI) issum(i, vss) = {nb = 0; for (j = 1, #vss, if (vss[j] > i, break); for (k = 1, j, sv = vss[j] + vss[k]; if (sv == i, nb++); if (sv > i, break); ); ); return (nb == 1); }
lista(nn) = {vec = vector(nn, i, i); vss = select(i->((precprime((i-1)/2) + nextprime(i/2) == i) && (i>2)), vec); for (i = 1, nn, if (issum(i, vss), print1(i, ", ")); ); } \\ Michel Marcus, Oct 14 2013

Crossrefs

Cf. A001043, A134651, A135045.

Sequence in context: A219110 A226024 A134651 * A102502 A309304 A345508

Adjacent sequences: A135545 A135546 A135547 * A135549 A135550 A135551

Keyword

nonn

Author

Zak Seidov, Feb 15 2008

Extensions

Example, corrected and extended by Michel Marcus, Oct 14 2013

Status

approved