DNA pattern: summing up consecutive locations

sums2 = posvec[2:length(posvec)]+posvec[1:(length(posvec)-1)]
sums3 = posvec[3:length(posvec)]+posvec[2:(length(posvec)-1)]+posvec[1:(length(posvec)-2)]
sums4 = posvec[4:length(posvec)]+posvec[3:(length(posvec)-1)]+posvec[2:(length(posvec)-2)]+posvec[1:(length(posvec)-3)]
sums5 = posvec[5:length(posvec)]+posvec[4:(length(posvec)-1)]+posvec[3:(length(posvec)-2)]+posvec[2:(length(posvec)-3)]+posvec[1:(length(posvec)-4)]
par(mfrow=c(2,2))
hist(sums2, main="Histogram of sums: 2 consecutive palindromes", xlab="")
hist(sums3, main="Histogram of sums: 3 consecutive palindromes", xlab="")
hist(sums4, main="Histogram of sums: 4 consecutive palindromes", xlab="")
hist(sums5, main="Histogram of sums: 5 consecutive palindromes", xlab="")