A264023 Suppose k is the concatenation of two integers, x and y: k = concat(x,y); a(n) is the smallest value of k such that x+y = prime(n).

11, 12, 14, 16, 29, 49, 89, 109, 122, 128, 130, 136, 140, 142, 146, 152, 158, 160, 166, 170, 172, 178, 182, 188, 196, 299, 499, 899, 1009, 1049, 1126, 1130, 1136, 1138, 1148, 1150, 1156, 1162, 1166, 1172, 1178, 1180, 1190, 1192, 1196, 1198, 1210, 1222, 1226, 1228, 1232

Offset

1,1

Links

Table of n, a(n) for n=1..51.

Prog

(PARI) vsums(k) = {vs = []; for (j=1, #digits(k)-1, vs = concat(vs, k\10^j+k % 10^j); ); vs; }
isokvs(vs, n) = for (j=1, #vs, if (vs[j]==n, return(1))); return(0);
findp(n) = {p = prime(n); k = 10; ok = 0; while (!ok, vs = vsums(k); ok = isokvs(vs, p); if (! ok, k++); ); k; } \\ Michel Marcus, Nov 13 2015

Crossrefs

Cf. A000040, A007953.

Sequence in context: A210767 A182404 A234021 * A177902 A108722 A246139

Adjacent sequences: A264020 A264021 A264022 * A264024 A264025 A264026

Keyword

nonn,base,easy

Author

Giovanni Teofilatto, Nov 01 2015

Extensions

More terms and better definition from Altug Alkan, Nov 13 2015

Status

approved