OFFSET
1,2
COMMENTS
Consider the triangle formed by replacing each m in Pascal's triangle with sigma(m). Then this sequence consists of the least column indices of the terms that are equal to the sum of its NW and N neighbors, as in a Pascal triangle.
EXAMPLE
PROG
(PARI) T(n, k) = sigma(binomial(n, k));
isokT(n, k) = T(n-1, k-1) + T (n-1, k) == T(n, k);
isokn(n) = for (k=1, n-1, if (isokT(n, k), return(1)));
listak(nn) = for (n=1, nn, for (k=1, n-1, if (isokT(n, k), print1(k, ", "); break)));
CROSSREFS
KEYWORD
nonn
AUTHOR
Michel Marcus, Mar 21 2017
STATUS
approved